Croton billbergianus Müller Argoviensis (1865: 98)

Caruzo, Maria Beatriz Rossi & Cordeiro, Inês, 2013, Taxonomic revision of Croton section Cleodora (Euphorbiaceae), Phytotaxa 121 (1), pp. 1-41 : 21

10. Croton billbergianus Müller Argoviensis (1865: 98) ( Fig. 1A–D ). Type:— PANAMA. Colón: Portobelo, s.dat., J.I. Billberg 316 (holotype B†, lectotype S!, here designated, isolectotype F!) .

Croton grosseri Pax (1904: 290) . Type:— COSTA RICA. Carrilo , 300 m, 8/ 9 July 1889, H.F. Pittier & T.A. Durand 1206

(holotype not located, isotype A!, US!).

Croton billbergianus subsp. pyramidalis (Donnell Smith) G.L. Webster (1988: 1123) . Croton pyramidalis Donnell Smith

(1903: 7). Type:— GUATEMALA. Alta Veracruz : Río Dolores near Cubilgüitz, July 1901, H. von Türckheim 7974

( holotype US!, isotype K!) .

Shrubs to trees 2–10 m tall, sometimes climbing; latex orange; multiradiate, appressed-stellate and dendritic trichomes, usually porrect; branchlets cylindric, striate, floccose, dendritic trichomes. Leaves discolorous, with a pair of sessile saucer-shaped basilaminar glands; lamina 3–25 × 2–18 cm, elliptical, ovate to cordate, apex long acuminate to cuspidate, base slightly rounded to cordate, margin minutely serrate, with glands; upper surface glabrescent, scattered appressed-stellate trichomes, porrect, mainly on midvein, lower surface pubescent to sparsely pubescent, multiradiate and appressed-stellate, trichomes, usually porrect; venation pinnate, brochidodromous; petiole 1–5 cm long; stipules 0.1–1 cm long, entire, linear-lanceolate, deciduous. Inflorescences 7–22 cm long, terminal, rarely axilar, lax, apparently branched; inflorescence axis flattened, striate, floccose, dendritic trichomes; proximal cymules bisexual, with 1 pistillate flower and ca. 2 staminate flowers, distal cymules with ca. 2 staminate flowers; bracts 2–4 mm long, entire, linear, prophylls ca. 1 mm long, linear. Staminate flowers 0.7–1 cm long, subcampanulate, long pedicellate; pedicels 3–6 mm long; calyx 3–5 mm long, pubescent externally, appressed-stellate trichomes, glabrate internally; calyx lobes 5, united half of their length, then free for 1–2 mm, entire, equal, valvate, ovate, apex acute, margin villose; petals 3–5 mm long, spathulate, apex rounded, margin villose; disk 5-segmented; stamens ca. 16, filaments filiform, villose at the base, anthers ellipsoid; receptacle villose with simple trichomes. Pistillate flowers 6–8 mm long, campanulate, pedicellate; pedicels 2–3 mm long; calyx 4–6 mm long, pubescent externally, brown appressedstellate trichomes, glabrescent internally; calyx lobes 5, united at the base, then free for the terminal 3–5 mm, entire, equal, imbricate, ovate-lanceolate to triangular, apex acute to acuminate; petals absent; disk entire, deeply 5-lobed; ovary subglobose, hirsute-tomentose, appressed-stellate porrect trichomes; styles 3, multifid, united into a short column at the base, each one entire up to 1/3 of their length, then branching into ca. 24 terminal arms, covered by appressed-stellate trichomes, included in calyx. Fruits ca. 1.5 cm long, subglobose, warty, scattered appressed-stellate trichomes, calyx lobes inconspicuously accrescent, reflexed; seeds 4–6 mm long, ellipsoid, ribbed.

Distribution and habitat: — Croton billbergianus is widely distributed in Central America, reaching Mexico in North America and Colombia in South America. It is found in moist forests from sea level to about 800 m elevation.

Phenology:— Flowering in February–September, and November; fruiting in April–October and December.

Taxonomic notes: —This species differs from the others of Croton section Cleodora mainly by its apparently branched inflorescences and calyx lobes conspicuously reflexed.

Selected specimens examined: — MEXICO. Veracruz: Vicinity of playa escondida, 10 km N of Sotecomapan, 18º35’30’’N, 95º03’W, fl., 21 April 1983, M. Nee 26703 (DAV, F, MICH, NY, US, XAL) . BELIZE. Toledo: Punta Corda , 1 August 1980, J.D. Dwyer 15176 (DAV, MO) . COSTA RICA. Limón: Cantón de Pococí, Along the margin of Rio Corinto , approx. 1.5km S of where Hwy. 32 crosses the river, 10º12’14.1’’N, 83º53’16.1’’W, 1080 m, fl., 12 April 2006, B. Van Ee & M. Van Ee 595 (MICH, WIS) . GUATEMALA. Cortes: E shore of Lago de Yojoa , 7 mi S of Agua Azul, 2000 ft., fl., 1 August 1962, G.L. Webster et al. 12754 (DAV, MBM, MICH) . NICARAGUA. Zelaya: Nova Guinea , 11º46’N, 84º22’30’’W, 180 m, fr., 11 August 1982, M. Araquistain 3084 (DAV, HNMN) . PANAMA. Colón: Road to Rio Indios , 3 km S of Pina, elev. 50 m, 7 July 1976, G.A. Sullivan 134 (MO, VEN) . COLOMBIA. Antioquia: Disturbed forest area approx. 15 km southeast of Turbo near the highway to Chigorodó , elevation less than 100 m, fl., 31 March 1962, C. Feddema 2104 (MICH, NY, US) .

Figures

FIGURE 1. A–D. Croton billbergianus. A. Flowering branch, detail of foliar trichomes and extrafloral nectaries (Hernadez 100). B. Staminate flower (Hernadez 100). C. Fruit (Carballo 493). D. Seed (Carballo 493). E–H. Croton cajucara. E. Flowering branch, detail of foliar trichomes and extrafloral nectaries (Zarucchi et al. 2655). F. Pistillate flower (Rodriguez s.n.), G. Gynoecium (Rodriguez s.n.). H. Fruit (Caruzo & Riina 98).