Urophyllum pseudoschmidtii Yooprasert, Culham, Yahara, Tagane & Utteridge, 2022

Yooprasert, Sawita, Culham, Alastair, Tagane, Shuichiro, Yahara, Tetsukazu, Nguyen, Van Du, Nguyen, Khang Sinh & Utteridge, Timothy M. A., 2022, New species and new status of Urophyllum Wall. (Rubiaceae) from Cambodia and Viêtnam, Adansonia (3) 44 (11), pp. 91-114 : 110-113

Urophyllum pseudoschmidtii Yooprasert, Culham, Yahara, Tagane & Utteridge , sp. nov.

( Figs 13 ; 14 )

Urophyllum streptopodium Wall. in Pitard in H.Lecomte, Flore générale de l’Indo-Chine 3: 200 ( Pitard 1923), auct. non. Urophyllum streptopodium Wall. ex Hook.f ., The Flora of British India 3: 99 ( Hooker 1880), syn. nov.

Urophyllum pseudoschmidtii Yooprasert, Culham, Yahara, Tagane & Utteridge , sp. nov. is similar to U. schmidtii C.B.Clarke , but differs in its pistillate flowers, which lack staminodes which are always found in pistillate flowers of U. schmidtii . The species also differs in its staminate inflorescences, which are sessile umbellate and the flowers are seemingly sessile having very short pedicels; whereas U. schmidtii has pedunculate umbellate inflorescences and the flowers with conspicuous pedicels.

TYPE. — Viêtnam. HaTinh Province: Vu Quang National Park , along trail to the summit of Mt. Rao CO, 18°12’49.7”N, 105°23’42.8”E, 904 m elev., 21.VI.2016, Yahara et al. V 5618a (♀) (holo-, K! ; iso-, DLU n.v.; FU!) .

ADDITIONAL SPECIMENS EXAMINED. — Viêtnam. s.loc., 7.VI.1921, Hayata 205 (♀) ( P [ P 03922484]!). — Ha Tinh Province, Vu Quang NP, in transect line 2, 18°16’9.1”N, 105°21’17.5”E, 649 m elev., 24.VII.2015, Yahara et al. V 3614 (sterile) ( DLU n.v.; FU!); along trail to the summit of Mt. Rao CO, 18°12’49.7”N, 105°23’42.8”E, 904 m altitude, 21.VI.2016, Yahara et al.V 5618b (♂) ( DLV n.v.; K!; FU!). — Lam Dong Province, Grand PitonLang-Bian [Lang Biang], près du village de Beneur [near the village Beneur], 1500-2000 m elev., 15.II.1914, Chevalier 30836 (♀) ( P [ P 03922421]!); Lac Duong District, Da Chais Commune, Bidoup Nui Ba NP, Trail by Rangerstation Giang Ly, 12°8’49.1”N, 108°40’16.2”E, 1469 m elev., 1.VI.2019, Yooprasert et al. VN 99-1 (♂) ( BKF!); Da Nhim Commune, Bidoup Nui Ba NP, Trail next to Ranger station Dung Iar Gieng, 12°9’35.9”N, 108°32’10.1”E, 1621 m elev., 3.VI.2019, Yooprasert et al. VN 112-1a (♂) ( BKF!; K!); Yooprasert et al. VN 112-1b (♂) ( BKF!; HN!) .

ETYMOLOGY. — The specific epithet refers to its similar morphological characters to U. schmidtii .

DISTRIBUTION. — Viêtnam. Ha Tinh Province (Vu Quang National Park) and Lam Dong Province (Bidoup-Nui Ba National Park) ( Fig.3 ).

HABITAT. — Evergreen hill forest, lower montane forest, by stream; elev. c. 600-2000 m.

PHENOLOGY. — Collected in flower in June. Fruit is only known from two herbarium specimens collected in February and June.

CONSERVATION STATUS. — Vulnerable (VU)D2.The conservation status of Urophyllum pseudoschmidtii Yooprasert, Culham, Yahara, Tagane & Utteridge , sp. nov. is assessed using six specimens collected from four locations in Bidoup-Nui Ba National Park (IUCN category Ia) and Vu Quang National Park (IUCN category II). The other two specimens, Chevalier 30836 and Hayata 205, were not included due to lacking precise localities and old ages (in 1914 and 1921, respectively). The estimated AOO (16 km 2) of these six specimens is within the Endangered threshold, however the species is found in protected areas where the deforestation has limited chance. Even though, the estimated EOO (5135 km 2) is within the Vulnerable threshold, there is a big gap between these two National Parks that causing habitat fragmentation and meaning estimated EOO is not reflected the real species occurrence. Therefore, U. pseudoschmidtii Yooprasert, Culham,Yahara,Tagane & Utteridge , sp. nov. is rated as Vulnerable with restricted AOO (<20 km 2) and small number of locations found. This assessment could be reviewed to Near Threatened or Least Concern if there is an evidence of species existing in nearby area such as Nakai-Nam Theun National Park (Laos, IUCN category II) or Phong Nha-Ke Bang National Park (IUCN category II). DESCRIPTION

Shrub to 1 m high. Indumentum sparsely to densely hairy except leaves and corolla. Branches terete; young shoots flattened, ridged. Stipules caducous, present 1-2 nodes at shoot, linear-lanceolate to oblong-lanceolate, 1.0- 1.1 cm long, 0.8-1.4 mm wide, appressed to the stem but not folded, abaxially sparsely to densely hairy. Leaves chartaceous, ovate or elliptic, 10-13 cm long, 3.5-4.5 cm wide, apex acuminate, base cuneate to obtuse, adaxially glabrous, abaxially subglabrous, sparsely hairy with short hairs <1 mm long on midrib to tertiary veins, drying dark greenish brown adaxially, yellowish to dark green abaxially with brown midrib and yellow veins; secondary veins [6-]8-10 pairs, festooned brochidodromous, angle decreasing basally; tertiary veins mixed percurrent, angle decreasing exmedially and increasing basally, obtuse angle to the midrib; petioles 4-6 mm long, canaliculate, adaxially densely hairy on ridges, abaxially sparsely hairy. Inflorescence axillary, staminate plant sessile umbellate, bracts minute triangular c. 0.8 mm long, adaxially and abaxially sparsely hairy, pedicels very short c. 0.5 mm long, nectary disk dome shaped; pistillate plant sessile, pedunculated to two-tier umbellate, peduncle 0-1.5 mm long, rachis 1.5-2 mm long, bracts lanceolate leafy-like, 2.3-5.2 mm long, adaxially glabrous, abaxially densely hairy, pedicels 2.8-7.9 mm long, nectary disk annular. Staminate flowers calyx fused, lobes 5, 0.5-0.8 mm deep; corolla lobes 5, valvate, fused to form a tube at base approaching 1/3-1/2 their length, lobed c. 1.5 mm long, densely hairy at throat inside; stamens 5, filament fused to the corolla tube, anthers 2-celled, dorsifixed, introrse; pistillode present, ovary vestigial. Pistillate flowers calyx and corolla as staminate flowers; staminodes absent; style c. 1.9 mm long, sparsely scaly; stigma lobes 5, c. 1.4 mm long, covered with scales.

REMARKS

Urophyllum pseudoschmidtii Yooprasert, Culham, Yahara, Tagane & Utteridge , sp. nov. is recognised by its pistillate flowers without staminodes. The population in Bidoup-Nui Ba National Park has a distribution overlapping with U. lecomtei . However, the species differs from U. lecomtei by its petioles, densely hairy on canalicular ridges, abaxial surface of corolla glabrous and pistillate flowers lacking staminodes, instead of petioles with similar hair density all over, abaxial surface of corolla hairy and pistillate flower with staminodes as found in U. lecomtei . Other taxa found in the same area are U. bidoupense Yooprasert, Culham & Utteridge , sp. nov. and U. chinense subsp. latistipulum Yooprasert, Culham, Yahara & Utteridge , subsp. nov. The differences have been discussed earlier in both taxa.

Figures

FIG. 13. — Urophyllum pseudoschmidtii Yooprasert, Culham, Yahara, Tagane & Utteridge, sp. nov.: A, flowering branch; B, stipules; C, petioles; D, young stem; E-I, pistillate plant: E, inflorescences; F, flower bud; G, stigma positioning in a flower; H, adaxial corolla showing throat hairs arrangement; I, staminode; J-N, staminate plant: J, inflorescence; K, flower bud; L, opening flower (top view); M, corolla, abaxial side (M1), adaxial side showing stamens and throat hairs arrangement (M2); N, stamen;O, leaf lamina,abaxial side (O1) and adaxial side (O2). Drawn by Mahsarahka Rungkrajang.Drawn from: A-I, O, Yahara et al.V 5618a; J-M, Yahara et al. V 5618b. Scale bars: A, 1 cm; B-E, O, 3 mm; F-H, M, J-L, 1 mm; I, N, 0.5 mm.

FIG. 14. — Holotype of Urophyllum pseudoschmidtii Yooprasert, Culham, Yahara, Tagane & Utteridge, sp. nov.

FIG. 3. — Occurrences of Urophyllum annamense (Pierre ex Pit.) Yooprasert, Culham & Utteridge, stat. nov. (), U. brochidodromum Yooprasert, Culham & Utteridge, sp. nov. (), U. pulchristipulum Yooprasert, Culham & Utteridge, sp. nov. () and U. pseudoschmidtii Yooprasert, Culham, Yahara, Tagane & Utteridge, sp. nov. ().