Elatostema malipoense W.T.Wang & Zeng Y.Wu,, 2011

Wu, Zeng-Yuan, Wang, Wen-Tsai, Wang, Hong & Li, De-Zhu, 2011, Two new species of Elatostema (Urticaceae) from southeast Yunnan, China, PhytoKeys 7, pp. 57-62 : 59-61

Elatostema malipoense W.T.Wang & Zeng Y.Wu, sp. nov. Figs 1 A–E2D–G

Latin

Ob folia penninervia et capituli pistillati bracteas numerosas apice corniculatas species nova haec est similis Elatostema pseudobrachyodonto W.T.Wang, quod foliis supra puberulis, capituli pistillati receptaculo glabro, bractearum pistillatarum cornibus apicalibus majoribus 1.5-2 mm longis, bracteolis pistillatis viridibus minoribus 0.3-0.6 mm longis apice breviter ciliatis, acheniis longitudinaliter 4-costatis valde recedit.

Type.

China. Yunnan, Malipo county, Xiajinchang village Yunling, 23°10'6"N, 104°49'50"E, 1613 m, 05 Aug. 2010, Z. Y. Wu 10347 (Holotype: PE!; Isotype: KUN!).

Description.

Perennial herb. Stems erect, 30-50 cm tall, above sparsely short- puberulous near the node, unbranched. Stipules subulate or narrowly triangular, 0.1-0.2 mm long; leaves shortly petiolate, glabrous, petioles 1-6 mm long; leaf blade subchartaceous, obliquely oblong or narrowly obovate-oblong, 11-15 × 3-3.5 cm, both surfaces densely short strigose, cystoliths conspicuous, dense, bacilliform, 0.1-0.2 mm long, penninerved, lateral nerves 5-7-paired, base obliquely cuneate, apex cuspidate (entire), margin denticulate. Pistillate capitula solitarily axillary; peduncle ca. 8 mm long, short-puberulous; receptacle subquadrate or broadly oblong, 10-15 × 10-15 mm, 4-lobulate or irregularly 4-6-lobulate, short-puberulous; bracts ca. 75, deltoid or depressed-deltoid, 0.5-0.6 × 0.5-0.7 mm, ciliate, abaxial surface short-puberulous, apex with a subulate horn-like projections, 0.7-1 mm long; bracteoles membranous, whitish, semihyaline, narrowly obovate or oblanceolate, 0.5-1 mm long, apically long ciliate. Pistillate flower subsessile, tepals absent; pistil 0.8 mm long, ovary green, 3.5 mm long, stigma penicillate, ca. 4.5 mm long. Achenes ovoid, 0.6-0.7 × 0.4 mm, densely tuberculate. Staminate capitula not seen.

Ecology.

Elatostema malipoense is a scattered understory herb growing in moist clay soils in shady sites or near ravines at an altitude of ca. 1600 m, associated with Pilea insolens and some species of Ficus .

Distribution and conversation status.

Elatostema malipoense is an endemic species and has only been collected from the type locality around Xiajinchang village Yunling, Malipo county, Yunnan, where a population of ca. 200 individuals was observed in an area of 1 km2. According to IUCN red list criteria ( IUCN 2011), this new species should be classified as critically endangered (CR B2ab (iii); C2b).

Similar species.

Elatostema malipoense is a member of sect. Elatostema ( Wang 2011a). In having penninerved leaves and a pistillate capitulum with numerous corniculate involucral bracts, Elatostema malipoense resembles Elatostema pseudobrachyodontum W.T.Wang. Elatostema pseudobrachyodontum differs from Elatostema malipoense in having short-puberulous adaxial surface of the leaf blade, glabrous pistillate receptacles, pistillate bracts 1.5-2 mm long, and corniculate, pistillate bracteoles are green, 0.3-0.6 mm long, apex short-ciliate at the apex and achenes that are longitudinally 4-ribbed ( Wang 1995).

Etymology.

The species epithet 'malipoense' is derived from the name of the type locality, Malipo County, Yunnan Province, China.

Figures

Figure 1. A-E Elatostema malipoense W. T. Wang & Zeng Y. Wu. A Upper part of flowering pistillate stem B pistillate capitulum, seen from below C two pistillate involucral bracts D pistillatate bracteoles and pistillate flower E achene, (based on Z. Y. Wu 10347). F-I Elatostema pleiophlebium W. T. Wang & Zeng Y. Wu. F upper cauline leaf G staminate capitulum H staminate bracteole I staminate bracteoles and staminate flower bud, (based on Z. Y. Wu 10181).

Figure 2. A-C Elatostema pleiophlebium W. T. Wang & Zeng Y. Wu. A Specimen B staminate bracteole C stipule D-G Elatostema malipoense W. T. Wang & Zeng Y. Wu. D pistillate capitulum, seen from below E pistillate involucral bracts F pistillate bracteoles G achenes.