taxonID	type	description	language	source
4F6387C4DF6AE51DFCE7FEE6FED43835.taxon	description	Croton argyratus Blume var. hypoleucus Müll. Arg. (1864) 483; (1866) 526. — Lectotype (designated by Esser & Veldkamp 2008): Motley 758 (lecto K [K 000959191]!), Borneo, Banjarmasin. Croton argyratus Blume var. brevipes Müll. Arg. (1866) 527. — Lectotype (designated by Esser & Veldkamp 2008): Zollinger 3212 (lecto G-DC [G 00311485]!; isolecto A [00047510]!, G [G 00434384]!, [G 00434386]!), Indonesia, Java. Croton argyratus Blume var. gracilis Müll. Arg. (1866) 527. — Lectotype (designated by Esser & Veldkamp 2008): Zollinger 3809 (lecto G-DC [G 00311486] *; isolecto BM [BM 000630468]!, CAL [CAL 0000023639] *, G [G 00434385]!, W [1889 - 0074726]!), Indonesia, Bali.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF6AE51DFCE7FEE6FED43835.taxon	distribution	Distribution — Thailand, Malesia: Peninsular Malaysia, Sumatra (Aceh, Sumatera Utara, Sumatera Barat, Riau, Jambi, Sumatera Selatan, Lampung), Java, Borneo, Philippines, Sulawesi, Lesser Sunda Islands, Moluccas. Habitat & Ecology — Open areas, hill slopes and partly dis- turbed places in evergreen primary forest, secondary forest or mountain forest, at rocky streams and roadsides. Altitude: sea level to 1200 m. Flowering: April – June, September, December; fruiting: August – November, January. Affinities — Croton section Argyrati (Van Ee et al. 2015). Vernacular names — Kayu bulan (Burkill 1935), Kayu Pos- kas (Sumatera Utara), Kayu si marattimang (Sumatera Utara), Dada kedih (Aceh), Giyak putih (Lampung), Setima (Burkill 1935). Uses — Wood seemingly of little value, but in some areas of the Malay Peninsula used for building, or to keep fires going (Andaman Islands) as it smoulders for a long time. Decoctions of leaves and stem are used to cure diarrhoea, also given after childbirth (Burkill 1935).	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF64E51DFFA8FACEFBAB39A2.taxon	description	Resembling C. laevifolius vegetatively but differing in stipule shape and width (filiform, 0.3 – 0.5 mm wide in C. beccarii vs subulate, 0.5 – 1 mm wide in C. laevifolius), leaf indument (abaxially scattered trichomes in C. beccarii vs (sub) glabrous in C. laevifolius); also C. beccarii has shorter inflorescences (2 – 7 cm long vs 5 – 23 cm long), densely pubescent sepals and pedicels in pistillate flowers, and densely pubescent small, globose, hardly sulcate capsules (4 – 5 mm diam), while C. laevifolius has overall more glabrous inflorescences and larger distinctly 3 - lobed obovoid capsules (5 – 8 (– 13) mm high by 4 – 7 mm diam) with scattered trichomes. — Type: Beccari PS 973 (holo L [L. 2203857]!, iso FI-B!), Indonesia, Sumatera Barat, Sungei Bulu, Sept. 1878. Trees or shrubs, young branchlets densely pubescent, soon glabrescent. Indumentum consisting of creamy to amber stellate trichomes with a darker centre, 0.1 – 0.3 mm diam, flat to slightly erect, often with a short central porrect radius and 10 – 20 free radii. Stipules filiform to subulate, 2 – 6 (– 8) by 0.3 – 0.5 mm, densely pubescent on both sides, caducous. Leaves pseudo-verticillate; petiole 0.5 – 3.5 cm long, grooved above, with scattered trichomes to slightly pubescent (denser at very base and very apex); glands elevated to slightly stalked discs, lateral on the very apex of the petiole, 0.3 – 0.5 mm diam, elevation / stalk 0.1 – 0.4 mm high; blade elliptic, 7 – 15 by 3 – 7 cm, 1.6 – 2.6 (– 3) times longer than wide, chartaceous, base obtuse to acute, margin slightly serrulate to subentire, teeth 4 – 6 mm apart, without apical trichomes nor marginal glands, apex acuminate, adaxial side glabrous, abaxial side with scattered trichomes (denser near base and large veins), epidermis visible; venation distinct, sunken above, not triplinerved, secondary veins 7 – 11 pairs, higher order nerves slightly indistinct. Inflorescences 1 – 2 (– 5) per apical whorl, 2 – 7 cm long, erect, basally 1 – 18 pistillate flowers, rarely 1 or 2 staminate flowers at the same node as a pistillate flower, apically 1 – 2 staminate flowers per node; bracts triangular-ovate, c. 0.5 by 0.2 mm, slightly pubescent on both sides, with a patch of simple trichomes on apex, caducous. Staminate flowers 3.5 – 4 mm diam; pedicel 1 – 2 mm long, round to slightly flattened, slightly pubescent; sepals triangular-ovate, 1.5 – 2 by 1 – 1.5 mm, outside with scattered trichomes to slightly pubescent; petals oblong, c. 1.7 by 0.5 mm, outside glabrous; stamens c. 11, filaments 1 – 2 mm long, anthers c. 0.4 by 0.4. Pistillate flowers 3.5 – 4 mm diam; pedicel 0.5 – 1.5 mm long, densely pubescent; sepals triangular-ovate, 2 – 2.5 by 0.8 – 1.5 mm, slightly longer than ovary, outside densely pubescent, glabrescent near apex and margin, with a patch of very short simple trichomes on apex; petals absent; ovary 3 - lobed, globose, c. 2 by 2 mm long, sulcate, very densely yellowish pubescent to almost hispid; style nearly absent to 0.2 mm long, densely pubescent; stigmas c. 2.3 mm long, fused at base, once divided to c. 2 mm from apex. Capsules globose, 4 – 5 mm diam, rough, hardly sulcate, very densely yellowish pubescent; pericarp very thin (c. 0.1 mm). Seeds probably obovoid, c. 3.5 by 2 mm, glabrous, likely carunculate. Distribution — Endemic to Sumatra (Sumatera Barat). Habitat & Ecology — Flowering: September. Affinities — Unknown, as molecular data are lacking, but morphologically highly similar to C. laevifolius (which is also not included in the phylogeny) and other species within the ‘ Riau pocket’ clade (Fig. 1: group I 4), based on the lack of colleters and similarities in trichomes and leaf shape. Note — The description of seeds and capsules is based on very limited material, only three capsules were present and one seed, all very distorted.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF64E51EFCE7FB7DFACD3C00.taxon	description	Croton pierrei Gagnep. (1922 ‘ 1921 ’) 558; (1925) 265. — Lectotype (designated here): Pierre 6233 (lecto P [P 00109484]!; isolecto A [00072716]!, BM [000551499] *, as Pierre s. n., E [E 00327460]!, G [G 00358191] *, as Pierre s. n., GH [00099664]!, NY [00262986]!, as Pierre s. n, P [P 00109485]!), Cochinchine, Prov. deTy-ninh, MontDeonba (perhapsalsoinK (K 000959153) *, as Pierre s. n., but locality missing). Remaining syntypes: Harmand 631 (P!), Vietnam, Nui-cam; Thorel s. n. (A!, P!), Laos, La-khon.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF64E51EFCE7FB7DFACD3C00.taxon	distribution	Distribution — Japan (Ryukyu Islands), Taiwan, S China, Thailand, Laos, Vietnam, Malesia: Malay Peninsula, Sumatra (Aceh, Sumatera Barat), Java, Borneo, Philippines, Sulawesi, Lesser Sunda Islands, Moluccas. Habitat & Ecology — In primary dry evergreen or mixed evergreen / deciduous forest, bamboo-hardwood forest, secondary forest, on rocky slopes, hills, also along streambanks, usually shaded; collected on limestone, sandstone, clayey substrate. Altitude: sea level to 600 m. Flowering and fruiting the whole year through. Affinities — The specimens present in our analysis and in that of Van Ee et al. (2015) showed a monophyletic species clade (Fig. 1: group H), part of a large polytomy with African, Asian, Australian and Pacific taxa. This species is not yet classified in any section, though Webster (1993) suggested either C. sect. Anisophyllum or C. sect. Monguia. Uses — Bark and roots are used as an antipyretic (Esser 2005). Notes — 1. Only one specimen from Sumatra was with fruit, therefore Thai specimens were used for describing the capsules and seeds. 2. An isotype of C. vidalii Airy Shaw (Vidal y Soler 555 in A [00100144]!) is C. cascarilloides, but the holotype (K [K 000959255] *) and another isotype (L [L. 2212494]!) are most certainly not C. cascarilloides and indeed C. vidalii.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF67E518FCE7FE98FAE43C00.taxon	description	Croton aromaticus Gaertn. (1791) 119 (‘ aromaticum ’), nom. illeg., non L. (1753). — Type: Not indicated.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF67E518FCE7FE98FAE43C00.taxon	description	Croton malvifolius Griff. (1848) 200. — Lectotype (designated here): Griffith 2518 (lecto BM [BM 000951453] *), Boutan (= Bhutan). Other syntype: Griffith 1166 (GH [00099667]!), Bootan (= Bhutan).	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF67E518FCE7FE98FAE43C00.taxon	description	Croton caudatus Geiseler var. oblongifolius Müll. Arg. (1866) 600. — Lectotype (designated here): Zollinger 642 (lecto GDC [G 00311913] *; isolecto A [00047516] *, [00106972]!, GDC [G 00311912]!, [G 00311921]!, G [G 00434381]!, [G 00434382]!, L [L 0234052]!), Indonesia, Java. Croton caudatus Geiseler var. hispidus Hook. f. (1887) 389 (‘ hispida ’). — Type: not indicated. Croton caudatus Geiseler var. ruminatus Hook. f. (1887) 389 (‘ ruminata ’). — Lectotype (designated here): Griffith s. n., 1845 (lecto K [K 000246831] *), India, Khasia Hills. Croton caudatus Geiseler var. globosus Hook. f. (1887) 389 (‘ globosa ’). — Type: not indicated. Croton caudatus Geiseler var. tomentosus Hook. f. (1887) 389 (‘ tomentosa ’). — Lectotype (designated here): Griffith s. n. (lecto K [K 000246826] *), India, Assam; other syntype: Wallich num. list no. 8938 (BM!, CAL [CAL 0000023625] *, K!, K-W!), India, Silhet. Croton caudatus Geiseler var. malaccanus Hook. f. (1887) 389 (‘ malaccana ’); Ridl. (1924) 259. — Lectotype (designated here): Griffth KD 4775 (lecto CAL [CAL 0000023572] *; isolecto: K [K 000246829] * without number, [K 000246830] * without number, [K 000959168] * without number, [K 000959169] * without number, [K 000959170] *, M [M- 0241964]!, GDC [G 00311922]!, GH [00099677]! without number, [00100129]! without number, W!, ZT!), Myanmar. Other syntype: Maingay KD 1376 (CAL [CAL 0000023573] *, GH [00047511]!, L [L 0233998]!, P!), Malaysia. Croton caudatus Geiseler var. harmandii Gagnep. (1925) 286. — Lectotype (designated here): Couderc s. n. (P [P 00610256] *), Cambodia, Vat-Preah. Other syntypes: Harmand s. n. (A [00047489]!, K [K 000959152] *), Cochinchine, delta du Mè-Không; Pierre s. n. (P n. v.) Cochinchine, Prov. de Bien-hoa. Croton caudatus Geiseler var. obovoideus N. P. Balakr. & Chakrab. (1985 ‘ 1983 ’) 190, f. 1. — Type: Sebastine 25343 A (holo MH, n. v.; isotypes MH [MH 00001136 *, MH 00001133 *, MH 00001135 *, MH 00001134 *), India, Kerala, Kottayam Dist., Velara.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF67E518FCE7FE98FAE43C00.taxon	distribution	Distribution — Pakistan, India, Sri Lanka, Bangladesh, Nepal, Bhutan, China (Yunnan), Myanmar, Thailand, Laos, Vietnam, Cambodia, Malesia: Malay Peninsula, Sumatra (Aceh, Sumatera Utara, Sumatera Barat, Sumatera Selatan, Banka-Belitung), Java, Borneo, Philippines, Sulawesi, Lesser Sunda Islands; Australia. Habitat & Ecology — In peat swamp forest, deciduous and evergreen forest, secondary forests and thickets, along rivers and streams. Altitude: sea level to 700 m. Flowering and fruiting the whole year through. Affinities — The sole member of Croton section Caudati (Van Ee et al. 2015). Uses — Mainly medicinal, a root decoction is used for purg- ing the intestines, also used when the person has a cold or is feverish, in combination with Plumbago the decoction can act as abortifacient. The leaves can also be used as poultice with fevers. Twigs are used in basketry (all Burkill 1935). In Indonesia, dried bark is used to relieve stomach disorders (Esser 2005). Notes — 1. Highly diverse in density of indumentum and size and amount of muricae on the capsules. Only one Sumatran collection with a pistillate flower, therefore material from the Malay Peninsula was also used. Only specimen Elbert s. n. (L. 2211126) has a small gland on two floral bracts. 2. The type sheets of Croton caudatus var. obovoideus, Sebastine 25343 at MH, were later numbered B – D by Chakrabarty, but these are not part of the original collection numbers, all sheets are clearly duplicates of the same gathering.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF61E519FCE7FE98FDFF3C1F.taxon	distribution	Distribution — Malesia: Sumatra (Sumatera Utara, Riau, Jambi, Sumatera Seletan), Borneo (Sarawak). Habitat & Ecology — Altitude c. sea-level to 50 m. Flowering: March, April, October; fruiting: February. Affinities — Part of the ‘ Riau pocket’ clade (Fig. 1: group I 4). Vernacular name — Tjongheul (Jambi). Note — Very limited material from Sumatra was found and none of the specimens had both staminate and pistillate flowers. Croton coriifolius is described from Borneo, where it only occurs in kerangas (heath) forests (low and species-poor forest on poor sandy soil; the last author has been there and has seen it). It is unclear where the Sumatran material was collected, and kerangas forest is not known from Sumatra (with the excep- tion of Banka and Biliton Islands), thus the identification of the Sumatran material has to be treated with caution (hence the cf. with the name). Many taxa have thicker leaves under the acid kerangas conditions, therefore Airy Shaw (1974 a) indicates that this species might be a sclerophyllous ecotype of C. oblongus, which is a very doubtful species (see Discussion).	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF60E519FFA8FE98FBE83C46.taxon	distribution	Distribution — Malesia: Malay Peninsula, Sumatra (Atjeh, Sumatera Barat, Bengkulu). Habitat & Ecology — In primary lowland (Dipterocarp) rain- forest, found on ridges and alluvial soil. Altitude: 100 – 700 m. Flowering: June; fruiting: February. Affinities — Riau pocket group (Van Ee et al. 2015), part of a polytomy (Fig. 1: group I 4), thus close affinities are unknown. Notes — 1. Gage (1922) made a later homonym for a Linne- an name (Linnaeus 1759) and mentioned two syntypes, Ridley 12176 and Ridley 12194 (SING). Li (1994) restored the error by using a new name. He regarded Ridley 12176 as the holotype, thus indirectly creating a lectotype. 2. Only six specimens (of which one as uncertain) were seen, of them only one specimen had a pistillate flower, one with a fruit, one with seed and one with an almost matured staminate flower, which was too fragile to measure the stamens. 3. Outside L only known from three collections, of which two collections are named by Gage (1922) and Li (1994), Ridley 12176 & 12194, both from the Malay Peninsula, Johor, Gunong Pulai. Besides these two Ridley collections there are also Sinclair 7277 (E [E 00201750] *, US [01246063] *) and Sinclair SFN 39510 (SING *), Malay Peninsula, Gunong Pulai (summit). The specimen at US is incorrectly placed under Croton lucidus L. (in error for C. lucidus Gage).	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF60E51AFCE7FEDEFED839E0.taxon	distribution	Distribution — Thailand, Malesia: Malay Peninsula (Perak, Selangor, Pahang, Terengganu, Johor), Sumatra (Sumatera Barat (Siberut), Kepulauan Riau (Singkep )), Borneo. Habitat & Ecology — In evergreen forest and along streams, on granite bedrock. Altitude: 40 – 850 m. Flowering: February – April; fruiting: July, August. Affinities — Riau pocket group (Van Ee et al. 2015; clade I 4 in Fig. 1). Uses — A decoction of the leaves is used in Malaysia as bath after childbirth (Esser 2005). Notes — 1. The leaves usually dry into a typical yellowish brown colour. The species is not known from the main island of Sumatra; one specimen is known from Pulau Singkep (one of the Riau islands) and the other from Pulau Siberut (Mentawai islands, west of Sumatra). Other specimens examined are from Sarawak and Malay Peninsula. 2. Three specimens were wrongly determined as C. erythrostachys. The main differences between these two species are that C. erythrostachys has marginal leaf glands on a long stalk and large trichomes (0.6 – 07 mm diam) with 9 – 10 radii spreading in all directions. The flowers and capsules of C. griffithii are smaller and less hairy.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF63E51AFFA8FAB8FC2A387A.taxon	distribution	Distribution — Malesia: Malay Peninsula, Sumatra (Sumatera Utara, Lampung), Borneo, Philippines, Moluccas. Habitat & Ecology — In primary forest, mangroves, swamp forests and on riverbanks, always near water. Altitude: sea level to 90 m. Flowering: unknown for Sumatra; fruiting: August. Affinities — Croton section Furcaria (Webster 1993). Croton heterocarpus groups together with C. macrocarpus (Fig. 1: group I 1), which might also be classified in this section, though the sections of Webster (1993) are not always recognized after phylogenetic analyses. Vernacular names — Borneo: Djingah berkosah. Uses — Roots are used as medicine in Sabah (N Borneo, Neil 7064).	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF63E51BFCE7FA02FED93852.taxon	description	Erect, annual herbs, to 40 cm high; whole plant with hispid, irritating trichomes. Indumentum consisting of stellate-porrect, whitish to pale brownish trichomes, 0.6 – 1.5 mm diam on leaves, up to 3 mm diam on stems, flat but usually with distinctly longer central porrect radius, with 6 – 12 (on adaxial side often only 2 – 6) free radii. Stipules filiform, 4 – 7 by 0.2 – 0.5 mm, with scattered trichomes, quite persistent. Leaves alternate below, but crowded to pseudo-verticillate on apical branches; petiole 0.5 – 2 (– 4) cm long, flattened, slightly sulcate, hispid; glands as stalked discs lateral-abaxial on the petiole / blade junction, stalk 0.5 – 1.5 mm long, 0.2 – 0.4 mm diam; blade ovate, 1.9 – 5.4 by 1.1 – 4.1 cm, 1.1 – 2.1 times longer than wide, chartaceous, base rounded to obtuse, margin double serrate, apex acute, adaxial side with scattered trichomes to slightly hispid, abaxial side densely hispid; venation distinctly triplinerved, indistinct and sunken on adaxial side, distinct on abaxial side; secondary veins 3 – 5 pairs, not looped and closed near margin. Inflorescensces thyrsoid, 2 – 5 cm long, erect, basal 2 – 7 (– 12) nodes with a pistillate flower, never staminate flowers in the same cymule of a pistillate flower; bracts filiform, 1.5 – 4 by 0.1 – 0.3 mm, scarcely hispid, with 1 – 3 pairs of filiform, gland-tipped, free or partly fused lobes at base. Staminate flowers c. 2 mm diam; pedicel c. 1 mm long, slightly flattened, hispid; sepals ovate, c. 1 by 0.5 mm, hyaline, outside pubescent, with a patch of simple trichomes on apex; petals oblong, c. 1 by 0.3 mm, hyaline, outside glabrous, inside slightly lanate; stamens 10 or 11, filaments 0.5 – 1 mm long, slightly fused at base, subglabrous, anthers c. 0.4 by 0.4 mm. Pistillate flowers c. 2 mm diam but soon to 5 – 7 mm diam; pedicel c. 0.3 mm long (up to 2 mm in fruit), hispid; sepals obovate, c. 1.5 by 0.5 mm, soon elongating to 3.5 – 4 by 1 – 1.5 mm (up to 7 by 2 mm in capsules), fused at the base, spreading at the apex, hispid outside, glabrous inside, longer than ovary; petals absent; ovary globose, c. 2 by 2 mm, hispid; stigmas c. 1.5 mm long, once divided to c. 1.4 mm from apex. Capsules subglobose, 3 – 4.5 by 2.5 – 4 mm, smooth, slightly sulcate, sparsely pubescent; pericarp very thin (c. 0.1 mm); columella 2.5 – 3 mm long. Seeds globose, slightly flattened, c. 3 by 2 mm, variously mottled, shiny but minutely reticulate-foveolate, carunculate. Distribution — Native to C and S America; introduced and naturalizing in W and E Africa, Sri Lanka, Thailand, throughout Malesia including Sumatra (Sumatera Selatan). Habitat & Ecology — Weed on waste places, old plantations, roadsides. Altitude: sea level to 100 m. Flowering and fruiting: February, March, June. Affinities — Croton section Geiseleria subsection Geiseleria (Riina et al. 2021). Note — Podostachys hirta (L’Hér.) Klotzsch (1841: 194) is mentioned by Plants of the World Online (http: // www. plant- softheworldonline. org /) as a synonym, but Klotzsch indicates it as his own species (a nomen nudum) and there is no reference to L’Héritier de Brutelle, therefore, the name is not considered here to be a synonym.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF62E51BFFA8FA2DFB053A3D.taxon	description	Croton korthalsii Müll. Arg. (1866) 527. — Type: Korthals s. n. (holo L [L. 2203684]!), Indonesia, Borneo. Mallotus minahassae Koord. (1898) 626. — Lectotype (designated here): Koorders 196453 (lecto L [L. 2203657]!), [Indonesia,] Celebes, Prov. Minahasa, Menado, 1895.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF62E51BFFA8FA2DFB053A3D.taxon	distribution	Distribution — Malesia: Sumatra (Sumatera Barat, Riau, Sumatera Selatan, Banka-Belitung), Java, Borneo, Sulawesi, Lesser Sunda Islands. Habitat & Ecology — In rather open primary or secundary forest. On clayey, sandy soil or granitic sand. Altitude: 0 – 1000 m. Flowering: August – January, April; fruiting: May. Affinities — No sequence data are available, but morphologically highly similar to species in the ‘ Riau pocket’ clade (Fig. 1: group I 4), based on the lack of colleters and similarities in trichomes and leaf shape. Vernacular names — Kelangin (Banka-Belingtung). Note ― Croton laevifolius is considered to be a synonym of C. oblongus (see Discussion; e. g., Airy Shaw 1982 a). Croton oblongus forms a species complex from which various species could be split off for Sumatra. This complex needs further study in the remaining distribution area.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF62E504FCE7F8C0FE2F3552.taxon	description	Croton macrocarpus Ridl. (1925) 332 (non Rchb. ex Müll. Arg. (1866) 698, nom. nud.). — Croton grandifructus Radcl. - Sm. & Govaerts (1997) 187, nom. superfl., see note 2. — Lectotype (designated here): I. H. Burkill 6519 (lecto K [K 000959163] *; isolecto A [00105623] *), Malaysia, Selangor, Telok Forest Reserve, Klang. Treelets, c. 6 m tall, dbh c. 10 cm; young branchlets densely pubescent, hardly glabrescent. Indumentum consisting of creamy to amber stellate trichomes with a darker brown centre, 0.3 – 0.6 mm diam (up to 1.2 mm on ovary), often slightly porrect, with one short central radius and 6 – 12 free radii. Stipules ensiform to subulate, 5 – 8 by 0.5 – 0.8 mm, densely pubescent on both sides, soon caducous. Leaves alternate; petiole (3 –) 6 – 13 cm long, round, slightly sulcate, at most slightly grooved above, densely to slightly pubescent; glands 1 or 2 pairs of distinctly stalked discs, lateral abaxially on the very apex of the petiole, 0.5 – 1 mm diam, stalk 0.3 – 1 mm long (Fig. 2 d), additional smaller marginal glands common, 0.3 – 0.6 mm diam, stalk 0.2 – 0.5 mm long; blade elliptic, 15 – 30 (– 35) by 5 – 10 cm, 2.8 – 3.6 times longer than wide, chartaceous to subcoriaceous, base subcordate, margin (sub) serrate, teeth 2 – 6 mm apart, apex acuminate, adaxial side glabrous, but midrib pubescent, abaxial side slightly to densely pubescent, surface always visible except in very young leaves; venation distinct, raised on both sides, basally not to indistinctly triplinerved, secondary veins 13 – 17 pairs, higher order veins distinct on both sides. Inflorescences 1 – 4 per node, 11 – 35 cm long, erect, densely pubescent all over, basally 20 – 30 pistillate flowers, rarely 1 – 2 staminate flowers in the cymule of a pistillate flower, apically 1 – 4 staminate flowers per node; bracts narrowly triangular, 2 – 3.5 by 0.5 – 1.5 mm, outside with scattered trichomes, with a patch of simple trichomes on apex, inside glabrous, soon caducous. Staminate flowers 5 – 6 mm diam; pedicel 3 – 9 (– 11) mm long, round, densely pubescent; sepals triangular-ovate, c. 2.5 – 3 by 1.5 – 2 mm, outside pubescent near base to glabrous near apex, inside glabrous; petals oblong, 2 – 2.3 by 0.7 – 1 mm, outside glabrous; stamens c. 15, free, filaments 3 – 4 mm long, anthers c. 1 by 0.5 mm. Pistillate flowers 10 – 13 mm diam; pedicel c. 4 mm long (to 10 mm in fruit), sulcate, densely pubescent; sepals triangular-ovate to narrowly triangular, 4.5 – 6 by 2 – 3 mm, outside densely to slightly pubescent, with a patch of short simple trichomes on apex, much longer than ovary; petals triangular-ovate to ensiform, 2 – 2.5 by 0.4 – 0.7 mm, outside densely pubescent, hispid on margin and apex, not caducous; ovary globose, 3.5 – 5 by 3 – 4 mm, densely yellowish hispid, style absent, stigmas c. 7 mm long, once divided to c. 5.5 mm from apex, slightly pubescent near base. Capsules cylindrical globose, slightly trilobate, c. 28 mm high, c. 22 mm diam, sulcate, densely pubescent; pericarp very thick (c. 1.5 mm) and woody; columella c. 23 mm long. Seeds obovoid, heavily flattened, c. 19 by 13 mm, with a groove on the inside, glabrous, carunculate. Distribution — Malesia: Malay Peninsula, Sumatra (Aceh). Habitat & Ecology — Partly logged-over forest, dry land forest on rolling hills, yellow-red loamy soil. Altitude: c. 30 – 40 m. Flowering: August; fruiting: August. Affinities — Related to C. heterocarpus (Fig. 1: group I 2) and should be classified in C. section Furcaria (Webster 1993), though that section still has to be corroborated phylogenetically. Notes — 1. Only one collection from Sumatra (de Wilde & de Wilde­Duyfjes 20590, L) and one from the Malay Peninsula (Burkill 6519, A, K). 2. Radcliffe-Smith & Govaerts (1997) assumed that Müller’s name (1866) was correct and regarded Ridley’s name (Ridley 1925) as a later incorrect homonym. However, Müller only noted the name without a description, which makes it an invalid name. Therefore, Ridley’s name is correct and Radcliffe-Smith & Govaerts created a superfluous name (see Esser 2002 a: 21). 3. Two sequences, duplicates of the same collection, were used in the phylogenetic analysis. These showed up as a trichotomy in the cladogram (Fig. 1) with one specimen of C. heterocarpus. However, the branches leading to the two entries of C. macrocarpus are very short, which proves that they belong to the same specimen indeed.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF7DE506FCE7FF06FF70388E.taxon	description	Lepidote trichomes present instead of stellate trichomes on the leaves and stems, differing from other species with lepidote trichomes (C. adumbratus, C. argyratus and C. cascarilloides) in the not completely covered abaxial leaf side (still epidermis visible in C. scaleus). Differs from C. cf. coriifolius based on larger and differently shaped stipules and small stalked leaf glands, whereas C. cf. coriifolius has larger and sessile leaf glands. Differs from C. laevifolius in the stellate trhichomes of up to 20 free radii, whereas the lepidote trichomes of C. scalaeus have more, 2 – 40, completely fused radii. The number of secondary veins in leaves of C. scalaeus is much higher than in the other species. — Type: Haviland & Hose 1846 (holo L [L. 2212508]!; iso L [L. 2212509]!), Malaysia, Sarawak, 1 st division, Kuching, 22 Feb. 1952. Paratypes: Buwalda 6681 (L [L. 2203308]!), Indonesia, Sumatra, Riau, road from Sungei Berapit to Pekan Heran; George et al. S 58358 (L [L. 2210922!]), Malaysia, Borneo, Sarawak, Sri Aman Div., Selepong Lop, Rumah Ungin; Pereira et al. 835 (L [L. 2210921]!), Malaysia, Borneo, Sabah, Keningau, Nabawan, near Mukim Labau; Yates 2227 (L [L. 2203859]!), Indonesia, Sumatra, Sumatera Utara, Asahan, Kwala Masihi. Woody, shrubs or trees; young branchlets slightly pubescent, soon glabrescent. Indumentum consisting of lepidote trichomes on stems and leaves, 0.1 – 0.3 mm diam, flat, with 20 – 40 (very hard to count) fused radii, and stellate to stellate-lepidote trichomes on inflorescences, 0.2 – 0.3 mm diam, flat, with 8 – 15 free to slightly fused radii. Stipules linear, 3 – 8 by 0.5 – 1 mm, with scattered trichomes to slightly pubescent, caducous. Leaves pseudo-verticillate; petiole 1 – 4 cm long, deeply grooved above, with scattered trichomes; glands lateral on the very apex of the petiole, slightly stalked to sessile but elevated, 0.4 – 0.8 mm diam, stalk 0.1 – 0.5 mm long; blade elliptic to slightly obovate, 7.5 – 13.5 by 3 – 6 cm, 2 – 2.6 times longer than wide, chartaceous to subcoriaceous, symmetric, base attenuate to obtuse but with very base attenuate, margin subentire, with hair patches or glands, apex acuminate, adaxial side glabrous, abaxial side with scattered trichomes near base, apically subglabrous, epidermis visible; venation distinct, sunken above, basally not triplinerved, secondary veins 9 – 13 pairs, higher order veins distinct below. Inflorescences 1 – 4 per node, 6 – 22 cm long, erect, basally up to 20 pistillate flowers, apically 1 – 5 staminate flowers per node; axis sulcate, subglabrous; bracts triangular-ovate, c. 1.5 by 0.5 mm, (sub) glabrous except for patch of simple trichomes on apex, caducous. Staminate flowers 3 – 4 mm diam; pedicel c. 2 mm long, round, glabrous; sepals triangular-ovate, c. 2 by 1 mm, outside; petals oblong, c. 2.2 by 0.5 mm, lanate on margin near apex, trichomes point- ing inwards; stamens c. 11, free, filaments 2.5 – 3.5 mm long, anthers c. 0.5 by 0.3 mm. Pistillate flowers 3 – 3.5 mm diam; pedicel 2 – 3 mm long, with scattered trichomes; sepals triangular-ovate, 1.5 – 1.8 by 1 – 1.5 mm, longer than ovary, (sub) - glabrous except for a small patch of simple trichomes on apex; petals absent; ovary obovoid, c. 2 by 2 mm, deeply sulcate, slightly to densely pubescent; style absent; stigmas c. 1.5 mm long, apically once divided to c. 1 mm from apex, glabrous. Capsules 3 - lobed, obovoid, 3 – 6 by 3 – 6 mm, lobes conchiform, deeply sulcate, with scattered trichomes, apex depressed; pericarp c. 0.2 mm thick; columella c. 5 mm. Seeds ellipsoid, 5 – 6 by 3.5 – 4.5 mm, glabrous, with a small caruncle. Distribution — Malesia: Sumatra (Sumatera Utara, Riau), Borneo (Sarawak, Sabah). Habitat & Ecology — Primary and secondary forest, kerangas. Altitude: close to sea level. Flowering: September, February, April; fruiting: September. Affinities — Unknown, as the sequence data are lacking, but morphologically highly similar to the species in the ‘ Riau pocket’ clade (Fig. 1: group I 4), based on the lack of colleters and similarities in trichomes and leaf shape. Vernacular name — Ambin bua (Riau). Note — The description is only based on two specimens from Sumatra, both with sparse inflorescences, and four specimens from Borneo. Distinctly different from other species in the C. oblongus complex by the presence of lepidote trichomes with a high number of fused radii instead of stellate trichomes with free radii.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF7FE506FFA8FA09FA1E3A2E.taxon	description	Characteristic for C. simalurensis are stalked leaf glands placed abaxially at the very base of the leaf, close to but not on the midrib; scattered but distinct trichomes on abaxial leaf side; large densely pubescent 3 - lobed oblate capsules. Croton simalurensis was confused with C. laevifolius but can easily be distinguished by the location of leaf glands, as C. laevifolius has them on the apex of the petiole instead of the leaf blade. — Type: Achmad 298 (holo L [L. 2203305]!; iso U [U. 1256144]!), Indonesia, Sumatra, Aceh, Simaloer (Simeulue). Paratypes: Achmad 99 (U [U. 1256142]!); Achmad 286 (L [L. 2203303]!, U [U. 1256145]!); Achmad 299 (L [L. 2203304]!, U [U. 1256143]!); Achmad 482 (L [L. 2203861]!); Achmad 870 (L [L. 2203858]!); Achmad 1100 (U [U. 1256146]!); Achmad 1780 (L [L. 2203850]!), all Achmad collections from: Indonesia, Sumatra, Simaloer; Rahmat Si Boeea 9364 (L [L. 2203848]!), Indonesia, Sumatra East Coast, Asahan, Aek Moente; Rahmat Si Boeea 9519 (L [L. 2203849]!), Indonesia, Sumatra East Coast, Asahan, Tor Ma- toetoeng; Rahmat Si Boeea 10029 (L [L. 2203846]!), Indonesia, Sumatra East Coast, Asahan, Tomoean Dolok. Woody, probably shrubs or trees; young branchlets densely pubescent, only partially glabrescent. Indumentum consisting of stellate trichomes, yellowish brown in the centre with whitish radii, 0.3 – 0.6 mm diam (0.1 – 0.6 mm diam on stems and capsules), flat (sometimes not flat on stems), with a central porrect radius, with (8 –) 15 – 25 free (or fused) radii. Stipules ensiform to subulate (occasionally narrowly triangular), 3 – 7 (– 9) by (0.4 –) 0.8 – 1.5 mm, densely pubescent on both sides. Leaves alternate; petiole (0.5 –) 1 – 5 cm long, slightly grooved above, with scattered but distinct trichomes to puberulous; glands abaxially at the very base of the leaf, close to but not on the midrib, slightly to distinctly stalked discs, (0.4 –) 0.6 – 1 mm diam, stalk 0.1 – 0.3 mm long; blade elliptic to obovate, 5.5 – 18 by 2.7 – 7.5 cm, 1.7 – 2.8 times longer than wide, chartaceous, base cuneate to obtuse, sometimes nearly rounded, margin in young leaves subserrate, soon almost entire, never with trichomes or glands at teeth, apex acuminate (rarely obtuse to rounded), adaxial side glabrous, abaxial side lighter than adaxial side when dried, trichomes scattered but distinctly pubescent (with surface always visible), more densely pubescent on the midrib and near the base, hardly glabrescent; venation distinct, sunken above, basally not triplinerved, secondary veins 8 – 10 pairs, higher order veins distinct below. Inflorescences 1 (– 4) per apical node, (7 –) 10 – 20 cm long, erect, basally 3 – 9 pistillate flowers, often 1 or 2 staminate flowers on same node as a pistillate flower, apically 1 – 4 staminate flowers per node; bracts triangular-ovate, 1.5 – 2.5 by 0.8 – 1.2 mm, subglabrous except for patch of simple trichomes on apex, quite persistent. Staminate flowers 3 – 4 mm diam; pedicel 1.5 – 4 mm long, round, with scattered trichomes to glabrous; sepals ovate, c. 2 by 1.5 mm, fused at base, subglabrous outside; petals oblong, c. 2 by 0.5 mm, outside glabrous; stamens 10 – 12, free, filaments 2.5 – 3.5 mm long, anthers c. 0.7 by 0.4 mm. Pistillate flowers 5 – 6 mm diam; pedicel 3 – 6 mm long with scattered but distinct trichomes to puberulous; sepals ovate to elliptic, c. 3 by 2 mm, fused at very base, apex acute, outside puberulous near base to glabrous near apex, with patch of simple trichomes on apex, inside glabrous, longer than ovary; petals filiform, c. 2 by 0.1 mm, usually absent; ovary globose, c. 2 by 2 mm, very densely yellowish pubescent, style less than 0.1 mm long; stigmas 2.5 – 4 mm long, thickened at base, once divided to 1.5 – 3 mm from apex. Capsules distinctly 3 - lobed, oblate, 7 – 9 mm high by 10 – 12 diam, lobes conchiform, heavily sulcate, surface rough, densely pubescent, apex slightly depressed; pericarp 0.4 – 0.6 mm thick; columella 6 – 7 mm long. Seeds ovoid, c. 6 by 5 mm, glabrous, carunculate. Distribution — Malesia: Endemic to Sumatra (Aceh (Simalur Isl.), Sumatera Utara). Habitat & Ecology — Altitude: to 1000 m. Flowering: January, March, June – August; fruiting: March, June, November. Affinities — Riau pocket group (Van Ee et al. 2015). Vernacular names — Dulu Dulu, Lasa-Lasa (Simalur); Kajoe depdep batoe (Rahmat Si Boeea 9364); Kayu Polir Aek (Sumatera Utara). Notes — 1. No ecological information is known from the collections of Sumatra, where it was mainly collected on Simalur island. 2. The capsules can be affected by insects and become galled, being larger and seemingly more than 3 - locular. Affected capsules are also less pubescent than regular ones and they are more oblate in shape. Highly affected capsules often have 1 to 3 holes in their pericarp possibly made by the insects.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF7FE507FCE7F8E9FBC83FC8.taxon	description	For other synonyms see World Flora Online (http: // www. plantsoftheworl- donline. org /); more will be incorporated when other regions of Malesia are treated. Shrubs or trees, to 6 m tall, diam to 15 cm; young branchlets with scattered trichomes, soon glabrescent. Indumentum consisting only of yellowish stellate trichomes, 0.2 – 0.9 mm diam on leaves, up to 0.5 mm on stems, flat, often with a short central porrect radius, with 9 – 15 free radii. Stipules filiform to ensiform, (0.5 –) 1.5 – 3 (– 4) mm long, densely pubescent on both sides to subglabrous, caducous. Leaves alternate; petiole 3 – 8 (– 10) cm long, hardly to shallowly grooved above, with scattered trichomes to subglabrous; glands always lateral on the basal leaf margin close to but not on the midrib, 0.5 – 1 mm diam, sessile to slightly stalked (always less than 0.5 mm long), marginal teeth often topped by colleters; blade ovate (to elliptic), 6 – 18.5 by 4 – 9 cm, (1.7 –) 1.9 – 2.3 times longer than wide, membranous, base obtuse with very base attenuate, margin slightly serrate to subentire, teeth 3 – 6 mm apart, without glands, apex mostly acuminate, sometimes acute, abaxial side slightly lighter then adaxial side when dry, with scattered trichomes to subglabrous on both surfaces, sometimes more densely pubescent at the very base of the bigger veins, epidermis visible; venation very distinctly triplinerved, actinodromous, with 3 (– 5) prominent basal veins, secondary veins 4 – 6 pairs. Inflorescences thyrsoid, 1 – 3 per whorl, (4 –) 7 – 13 cm long, erect, basally 4 – 10 pistillate flowers, sometimes 1 or 2 staminate flowers at the same node as a pistillate flower, apically 1 – 3 staminate flowers per node; axis with scattered trichomes to subglabrous; bracts triangular-ovate, 2 – 4 by 0.5 – 1 mm (staminate ones smaller than pistillate ones), quite glabrous, eglandular, caducous to persistent. Staminate flowers 4 – 4.5 mm diam; pedicel 3 – 5 mm long, subglabrous; sepals triangular-ovate, c. 2.5 by (1.5 –) 2 mm, subglabrous outside; petals oblong, c. 2 by 1 mm, glabrous outside; stamens 15 – 20, free, filaments 1 – 3.5 mm long, anthers c. 0.6 by 0.5 mm. Pistillate flowers 6 – 8 mm diam; pedicel 3 – 5 mm long, densely pubescent; sepals triangular, 2.5 – 3.5 by 1 – 2 mm, fused at base, apically spreading, slightly longer than ovary or as high, outside subglabrous, with a patch of simple trichomes on the very apex; petals absent; ovary distinctly 3 - locular, globose to slightly ovoid, 3 – 4 by 2 – 3 mm, densely pubescent; stigmas 4 – 6 mm long, once divided to 3 – 4 mm from apex. Capsules 3 - lobed, prolate, 18 – 25 by c. 15 mm, sulcate, surface with scattered trichomes to subglabrous; pericarp fragile and thin (less than 1 mm thick); columella c. 17 mm long. Seeds prolate, one side slightly flattened, c. 13 by 8 mm, glabrous, with small caruncle. Distribution — Naturally occurring in Sri Lanka, India, through SE Asia to China, and in Malesia from the Malay Peninsula to the Philippines and the Moluccas, though it is often not possible to ascertain if a specimen was collected in the wild (check https: // powo. science. kew. org / taxon / urn: lsid: ipni. org: names: 343631 - 1; last visited on 5 August 2022). Cultivated and introduced in North America and Africa. On Sumatra in Sumatera Utara, Sumatera Barat, Jambi. Habitat & Ecology — Mostly in evergreen secondary forest. Altitude: sea level to 1100 m. Flowering: May – October; fruiting: May – August. Affinities — Croton section Croton (Van Ee & Berry 2010 b). Vernacular names — Simalakian (Burkill 1935); Croton oil plant (English). Uses — Burkill (1935): Seeds or oil of seeds is used in very low doses (at most 1 seed or 1 drop) as purgatives, but very poisonous (blistering mouth and intestines if too much, blistering and inflamating skin); therefore also used for poisoning humans, and in hunting to stupefy fish or to make poison arrows (bark and leaves also suitable for that purpose). The seed oil can also be used for illumination, but only outdoors as the fumes are poisonous, same if the wood is used as firewood. Still, in former times planted for the seed oil, which was exported to Europe; today the market is limited to some medical treatments, especially for skin peeling.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
4F6387C4DF7EE500FCE7FD55FEE63A3C.taxon	description	Unique on Sumatra are the small and narrow leaves (2.5 – 7.2 by 0.7 – 2.2 cm), the few (4 – 6) secondary veins, the light green colour after drying, the short inflorescences (only 0.5 – 2.5 cm long) and very narrow pistillate sepals. — Type: Kleinhoonte 460 (holo L [L. 2212218]!), Indonesia, Sumatera Barat, Sarasah Bunta. Shrubs or trees; young branchlets densely pubescent, soon glabrescent. Indumentum consisting of whitish to yellowish brown stellate trichomes, 0.2 – 0.4 mm diam, flat, often with a short central porrect radius, with 15 – 25 free to slightly fused radii (occasionally completely fused on stems). Stipules triangular-ovate to ensiform, 0.6 – 2 by 0.2 – 0.8 mm, densely pubescent on both sides, caducous. Leaves alternate to apically crowded; petiole 0.3 – 1 (– 1.5) cm long, deeply grooved above, with scattered trichomes to slightly pubescent; glands as slightly stalked discs abaxially at the very base of the leaf (Fig. 2 c), close to but almost never on the midrib base, diam 0.2 – 0.4 mm, stalk 0.1 – 0.2 mm long; blade narrowly elliptic, 2.5 – 7.2 by 0.7 – 2.2 cm, 2.4 – 4.2 times longer than wide, chartaceous, symmetric, base obtuse, margin entire, flat (to slightly revolute), without glands, apex acute to obtuse, adaxially initially with scattered trichomes (more dense near large veins), glabrescent, abaxially with scattered distinct trichomes, epidermis visible; venation distinct, basally slightly to not triplinerved, secondary veins 4 – 6 pairs. Inflorescences thyrsoid, solitary per apical node, unisexual, 0.5 – 2.5 cm long; bracts triangular-ovate, c. 0.5 by 0.5 mm, slightly pubescent, caducous. Staminate flowers c. 3 mm diam; pedicel 1 – 2 mm long, round, subglabrous; sepals triangular-ovate, 1 – 1.5 by 0.5 – 1 mm, subglabrous outside, with a patch of simple trichomes on apex; petals ensiform, c. 1.8 by 0.3 mm, outside glabrous, lanate on margin and inside; stamens 10 or 11, free, filaments c. 1.5 mm long, anthers c. 0.4 by 0.5 mm, connective pilose. Pistillate flowers c. 3 mm diam; pedicel 1 – 2 mm long, sulcate, densely pubescent; sepals triangular, c. 1.4 by 0.8 mm, fused at the base, spreading at the apex, outside slightly pubescent (denser near base), with a patch of simple trichomes on apex, as high as to slightly shorter than ovary; petals absent; ovary 3 - lobed, subglobose, c. 1.2 by 1.4 mm, densely yellowish pubescent; style absent; stigmas c. 2 mm long, fused at base, once divided to c. 1.6 mm from apex. Capsules unknown, columella c. 4.5 mm long. Seeds young, likely with small caruncle. Distribution — Malesia: Endemic to Sumatra (Sumatera Barat). Habitat & Ecology — Habitat unknown. Altitude: c. 500 m. Flowering and fruiting: only known from August. Affinities — Riau pocket group (Van Ee et al. 2015). Notes — 1. Only known from one specimen, originally identified by Van Steenis as Croton verreauxii Baill. But the specimen shows limited to no similarity with the Australian specimens of C. verreauxii. 2. Most similar species are C. gageianus (also having short inflorescences and a narrow leaf blade) and C. simalurensis (due to similar indumentum and location of leaf glands) but C. viridifolius can easily be distinguished by the small leaves and few secondary veins. 3. The inflorescences appear as unisexual, but this is likely typical for this specimen.	en	Beyer, J., Esser, H. - J., Eurlings, M. C. M., Welzen, P. C. van (2023): A revision of the genus Croton (Euphorbiaceae) in Sumatra (Indonesia). Blumea 68 (1): 1-25, DOI: 10.3767/blumea.2023.68.01.01, URL: https://doi.org/10.3767/blumea.2023.68.01.01
