Elatostema planinerve and E. longicuspe spp. nov. (Urticaceae) from Guizhou Province, China

Fang Wen , Long-Fei Fu , Yi-Gang Wei and Wen-Tsai Wang

F. Wen, L.-F. Fu and Y.-G. Wei, Guangxi Key Laboratory of Functional Phytochemicals Research and Utilization, Guangxi Inst. of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences, CN-541006 Guilin, PR China. LFF also at: Th e Life Science College, Guangxi Normal Univ., CN-541004 Guilin, Guangxi, PR China. – W.-T. Wang (wentsaiwang@year.net), State Key Laboratory of Systematic and Evolutionary Botany, Inst. of Botany, the Chinese Academy of Sciences, CN-100093 Beijing, PR China.

Two new species, Elatostema planinerve W. T. Wang & Y. G. Wei sp. nov. and E. longicuspe W. T. Wang & Y. G. Wei sp. nov. are described and illustrated from the Guizhou province, China. Th e former resembles E. bracteosum but diff ers in leaves, pistillate bracts and pistillate bracteoles; the latter is similar to E. tenuicornutum , but diff ers in stem surface, leaf shape, venation, cystoliths, staminate infl orescence bracts, bracteolate and staminate fl owers.

Th e family Urticaceae consists of more than 46 genera, of which 22 occur in China. Th e genus Elatostema J. R. & G. Forst. is one of the largest genera, and is mainly distri-buted in tropical and subtropical regions of Africa, Asia and Oceania. Southern and southwestern China is one cen-ter of distribution for Elatostema . Many new taxa, including new series, species and varieties, have been described and illustrated in recent years: E. series Neriifolia W. T. Wang & Zeng Y. Wu (Wu et al. 2012), E. cucullatonaviculare W. T. Wang, E. luoi W. T. Wang, E. heterogrammicum W. T. Wang, E. fugongense W. T. Wang, E. bijiangense var. weixiense W. T. Wang (Wang 2012). So far, at least 238 species (200 endemic) and 29 varieties have been recorded in China (Wang 1995, Lin et al. 2003, Wu et al. 2012).

In 2010, we collected some Elatostema specimens from the Guizhou province in China. Two new species of this genus were identifi ed after thorough consultation of the literature and comparison of deposited specimens in PE, IBK and Kun.

Elatostema planinerve W. T. Wang & Y. G. Wei sp. nov. (Fig. 1)

Similar to E. bracteosum, but leaves glabrous with 4 – 5 pairs of lateral nerves, pistillate bracts ca 10, linear – lanceolate, not corniculate, and pistillate bracteoles not corniculate.

Type : China. Guizhou, Xingyi, limestone hillside under-growth, 31 Mar 2010, Wen Fang 1027 (holotype: PE, isotype: IBK).

Etymology Elatostema planinerve is named after its fl at nerves.

Description Perennial herb, terrestrial, probably dioecious. Stems 200 – 260 � 1.8 – 2.5 mm, decumbent, green, simple, glabrous, with internodes (6)19 – 31 mm long. Stipules narrowly lin-ear, 0.2 � 0.15 – 0.30 mm, glabrous. Leaves distichous, alter-nate, sessile or subsessile, glabrous; laminae (6)12 – 120 � 6 – 30 mm, length:width ratio 2 – 4:1, narrowly obovate – oblong or narrowly oblong, rarely narrowly elliptic, thinly chartaceous; nerves pinnate, lateral nerves 4 – 5, at 45 – 60 ° to the mid-rib; upper surface fl at, drying yellow green, sparsely hispid from hairs that are ca 0.5 mm long, weakly curved and appressed; cystoliths on upper surface dense, conspicu-ous, bacilliform, 0.05 – 0.20 mm long; lower surface incon-spicuous raised, drying yellow green, glabrous, without cystoliths; base asymmetrical, broader-half cuneate and narrower-half oblique cuneate; margin serrate with teeth 5 – 8 mm apart; apex long acuminate, acuminate or rarely acute, with entire acumen. Staminate infl orescences not seen. Pistillate infl orescence didymous, axillary; capitulum, sessile, ebracteate?; receptacle ca 1 mm in diameter, sub-tended by marginal bracts, bracts ca 10, subequal, linear – lanceolate, 0.7 – 1.0 � 0.5 mm, acute at apex, pubescent; bracteoles membranous, semitransparent, linear – lanceolate, ca 0.5 � 0.15 mm, pubescent at apex, virescent, with 1 green nerve. Pistillate fl ower short pedicellate; tepals inconspi-cuous; pistil ca 0.3 mm long; ovary narrowly ellipsoidal, ca 2.8 mm long; stigmas pubescent with 0.2 – 0.3 mm long hairs. Infructescence not seen.

Nordic Journal of Botany 31: 312–315, 2013

doi: 10.1111/j.1756-1051.2012.00034.x,

© 2013 Th e Authors. Nordic Journal of Botany © 2013 Nordic Society Oikos

Subject Editor: David Bouff ord. Accepted 26 September 2012

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Figure 1. Elatostema planinerve sp. nov. (A) habit, (B) pistillate capitulum, seen from beneath, (C) bracteole and pistillate fl ower. Drawn by Y. B. Sun from the holotype.

Distribution and ecology All plants seen grew on dark and moist crevices and rock surfaces of limestone caves in large karst caves in Xingyi, Guizhou province, China.

Similar species Elatostema planinerve is morphologically similar to E. bracteosum Wang (1980, p. 59), but diff ers in leaves, pistillate bracts and pistillate bracteoles as summarized in Table 1.

Elatostema longicuspe W. T. Wang & Y. G. Wei sp. nov. (Fig. 2)

Similar to Elatostema tenuicornutum but with glabrous stem, staminate infl orescences with bracts and bracteoles,leaves with

fewer lateral nerves and longer cuspidate apex, conspicuous sta-minate fl ower pistillode and absence of cystoliths.

Type : China. Guizhou: Zhenfeng County, Longtou Mountain Nature Reserve, 25 ° 24 ′ N, 105 ° 28 ′ E, 30 Mar 2010 Y. G. Wei & F. Wen 1049 (holotype: IBK, isotype: PE!).

Etymology Elatostema longicuspe is named after the long cuspidate apex of the leaf blade.

Description Perennial herb, terrestrial, dioecious. Not tuber forming. Stems ca 150 � 1.2 mm, decumbent, not succulent, dark green, glabrous, with internodes 8 – 12 mm. Stipules cadu-cous. Leaves distichous, alternate, terminal pair of leaves

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and narrower half cuneate; margin serrate with teeth 4 – 7 mm apart; apex long cuspidate. Staminate infl orescences solitary, 25 – 33 mm, capitulate, bearing 3 – 5 fl owers in a pedunculate receptacle; peduncle 15 – 23 � 0.1 – 0.3 mm, glabrous, ebrac-teate; receptacle small, ca 0.5 � 1.0 mm, upward unfolded, oval, glabrous, dark green above, dark green below, sub-tended by marginal bracts; bracts borne perpendicular to the receptacle, ca 10, subequal, ca 4 mm, ovoid, dark brown, with the abaxial apex corniculate, 0.4 – 1.0 mm, glabrous. Staminate fl owers 2.8 – 3.0 � 1 mm immediately prior to anthesis, white, pedicellate, bracteolate; pedicel ca 2 mm, glabrous; bracteoles ca 4, membranous, semitransparent, white, equal, ca 4 mm, broadly linear, glabrous; tepals 5, ca 2 mm, the subapical appendage 0.7 mm, corniculate, broadly ovate, white, glabrous, connate at base; stamens 5, ca 2 mm, glabrous; anther 1 mm, oval; pistillode 0.2 mm, deltoid. Pistillate infl orescence solitary, axillary, ca 5.1 mm, capitate, sessile, ebracteate?; receptacle 1.0 � 1.0 mm, discoid, gla-brous, yellow above and below, subtended by marginal bracts; bracts 6, subequal, ca 2.5 mm, narrowly oval, gla-brous; bracteoles 0.8 – 1.0 mm, broadly linear, glabrous. Only young pistillate fl owers seen.

Figure 2. Elatostema longicuspe sp. nov. (A) upper part of fl owering staminate stem, (B) upper part of fl owering pistillate stem, (C) staminate bracteole, (D) staminate capitulum, (E) staminate fl ower, (F) infl orescence viewed from below with marginal bracts visible. Y.-G. Wei and F. Wen 1049, IBK. (A), (C) – (E) drawn from isotype by Ying-Bao Sun and (B), (F) are drawn from the holotype by Wen-Hong Lin.

subopposite, subsequent leaves subequal, subsessile or short petiolate; petioles 1.0 – 2.0 � 0.5 mm, glabrous; laminae 25 – 60 � 12 – 20 mm, length:width ratio 1:2.1 – 3.0, asym-metrically oblique ovoid, rarely oblique elliptic, chartaceous; venation pinnate with major basal lateral veins absent and lateral nerves in 4 pairs at 45 – 70 ° to the mid-rib; upper surface drying dark green, sparsely pubescent with 0.5 – 0.7 mm long hairs that are weakly curved and appressed, without cystoliths; lower surface drying green, glabrous, without cystoliths; base asymmetrical, broader half auriculate

Table 1. Morphological comparison between Elatostema planinerv e sp. nov. and E. bracteosum .

Characters E. planinerve E. bracteosum

Leaves with 4 – 5 - pairs of lateral nerves, glabrous

with 6 – 7 - pairs of lateral nerves upper surface sparsely hispid, lower surface pubescent

Pistillate bracts

ca 10, linear – lanceolate not corniculate

ca 8, narrowly triangular or linear, corniculate

Pistillate bracteoles

not corniculate corniculate

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infl orescence bracts and bracteolate, and staminate fl owers as summarized in Table 2.

Acknowledgements – We would like to acknowledge the support of the National Natural Science Foundation of China (grant no. 3116039) and the Science Research Foundation of Guangxi Institute of Botany (Guizhiye 11001 and 11003, no. 10004), supporting the fi eldwork. We thank Mr Sun Ying-Bao and Mr Lin Wen-Hong for the beautiful drawing and Prof. Fa-Nan Wei (IBK) for much help.

References

Lin, Q. et al. 2003. Eltostema (Urticaceae). – In: Wu, Z. Y. and Raven, P. H. (eds), Flora of China. Vol. 5. Science Press, Miss. Bot. Gard. Press, pp. 127 – 163.

Wang, W. T. 1980. Classifi catio specierum sinicarum Elatostematis (Urticaceae). – Bull. Bot. Lab. N-E. For. Inst. 7: 59 – 61.

Wang, W. T. 1995. Elatostema . – In: Wang, W. T. and Chen, C. J. (eds), Flora Reipubl. Pop. Sin. Vol. 23. Science Press, pp. 187 – 317.

Wang, W. T. 2012. Four new species and one variety of Elatostema (Urticaceae) from China. – Plant Divers. Resour. 34: 137 – 144.

Wu, Z. Y. et al. 2012. One new series with its only new species of Elatostema (Urticaceae) from southeast Yunnan, China. – Plant Divers. Resour. 34: 151 – 154.

Distribution and ecology Elatostema longicuspe grows in moist humus in crevices of sandstone and shale under subtropical evergreen broad-leaved forests in Zhefeng County, Guizhou Province, 1350 m a.s.l. Known only from the type locality in Zhenfeng County, Guizhou, southwest China.

Similar species Elatostema longicuspe is morphologically similar to E. tenuicornutum Wang (1980, pp. 60 – 61), but diff ers in stem surface, leaf shape, venation, cystoliths, staminate

Table 2. Morphological comparison between E. longicuspe sp. nov. and E. tenuicornutum .

Characters E. longicuspe E. tenuicornutum

Stem glabrous strigoseLeaf apex long and cuspidate acuminate or acuteVenation with 4 pairs of

lateral nerveswith 7 – 8 pairs of lateral

nerveCystolith absent denseStaminate

infl orescence bracts

ca 10, glabrous 2 – 6, abaxially pubescent

Bracteoles glabrous tricholomousStaminate fl ower

pistillodedeltoid inconspicuous

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