Zeuxine ovalifolia L. Li & S. J. Li

Li, Lin & Li, Shi-Jin, 2013, A new species of Zeuxine (Cranichidae; Orchidaceae) from Hainan, China, Phytotaxa 129 (1), pp. 65-68: 65-67

publication ID

http://doi.org/ 10.11646/phytotaxa.129.1.7

persistent identifier

http://treatment.plazi.org/id/2B7B87B1-FFC1-3C44-1BEA-4C2AFCAFFE26

treatment provided by

Felipe

scientific name

Zeuxine ovalifolia L. Li & S. J. Li
status

sp. nov.

Zeuxine ovalifolia L. Li & S. J. Li   , sp. nov. ( Fig. 1 View FIGURE 1 )

Species similar to Z. agyokuanae Fukuy   but with much smaller ovate leaves, broader and more sparsely ciliate floral bracts, narrower and united dorsal sepal and petals, and a yellow to orange-yellow hypochile of the lip with bi- or trilobed calli.

Type: — CHINA. Hainan Province: Wuzhishan Mountain National Nature Reserve , in tropical rainforest, 18° 53’ N – 109° 41’ E, 1,380–1,400 m, 1 September 2012, Li 0466 (holotype: IBSC!) GoogleMaps   .

A terrestrial herb with creeping rhizome and ascending leafy stem. Rhizome terrete, 5–6 cm long, rooting at nodes; internodes 1.2–2.0 cm. Roots arising from rhizome nodes, pubescent. Stem 4–5 cm tall, glabrous, enveloped by tubular, leaf-bearing sheaths. Leaves 6–7, cauline, alternate, sheathing petiolate; petiole and sheath 0.5–1.0 cm long; leaf blade ovate, margin entire, base rounded, apex acute, 1.6–2.2 × 0.7–1.0 cm, deep green to green, grayish-green beneath without white markings. Inflorescence terminal, erect, racemose, sparsely pubescent; peduncle ca. 9.5 cm long, with 2 sterile bracts, 4.0–7.0 × 0.5–1.0 mm, pinkish brown; rachis 3.0– 3.5 cm long, loosely spaced with 4–6-flowers. Floral bracts shorter than the ovary, tubular, redbrown, apex acuminate, margin sparsely ciliate or fringed, 6.0–6.5 × 1.5–2.0 mm. Pedicel and ovary fusiform, subglabrous, twisted, 7.5–8.0 × 0.8–1.5 mm, dark brown. Flowers about 6.0– 6.5 mm across, red-brown with a yellow and white lip. Sepals subglabrous, subsimilar; dorsal sepal 5.2–5.4 × 1.4–1.7 mm, oblong-lanceolate, concave below middle or near base, apex obtuse, red-brown; lateral sepals spreading, narrowly oblonglanceolate, 4.0–4.2 × 1.0– 1.4 mm, acuminate, margin slightly involute, apex obtuse, adaxially olive-green tinged red-brown, abaxially red-brown. Petals glabrous, oblique, slightly falcate, 4.8–5.0 mm long, broad in the middle, narrowing suddenly towards the apex, closely joined or united to the dorsal sepal forming a forward hood over column, white. Lip cymbiform, fleshy, saccate at base, 4.0– 4.3 mm long, 1.2–1.5 mm thick at base, with a short mesochile and tripartite, orange-yellow to bright yellow at base, white at apex (epichile); hypochile concave-saccate, ca. 3 mm long, inside bearing a pair of irregularly toothed warts on each side, honey yellow, bipartite or tripartite, somewhat dentate, apex obtuse; mesochile involute, folded inward, dentate to jagged along margin; epichile attenuate, narrower than hypochile, broad ligulate, 1.0– 1.2 mm, margins slightly inflexed, apex obtuse, strongly recurved. Column ca. 2.5 mm long, dilated toward apex, without appendages; rostellum 1.5–1.8 mm long, deeply cleft or bifid, thickened toward the apex and clavate; stigma 2, lateral. Anther ovoid-lanceolate, bilocular, 2.3–2.5 mm long, apex acuminate. Pollinia 2, narrowly clavate, granulose, bipartite and basally attenuate into caudicles, attached to a single oblong viscidium.

Distribution and habitat:— The species has a restricted distribution and is so far known only from the type locality. It occurs in shaded rainforests on moist soil covered with leaf litter.

Phenology:— Flowering from late August to early September.

Etymology:— The name of the species was chosen due to its ovate leaves.

Taxonomic remarks:— Zeuxine ovalifolia   overall is similar to Z. agyokuana Fukuyama (1934: 433)   from the Ryukyus Islands and northern Taiwan, but Z. ovalifolia   can be easily distinguished mainly in having much smaller ovate leaves (1.5–2.2 cm), alternate, not clustered apically, margin not undulate; broadly ovate bracts, margin sparsely ciliate towards the apex; falcate petals and conspicuously narrower, oblong-lanceolate dorsal sepal (index c. 5.5/1.7) entirely fused together, as compared to obovate petals and ovate dorsal sepal (index c. 4.0/2.8) connivent or adherent, overlapping each other, lip hypochile with warty, bi-trilobed calli, broad, not uncinate or hooked. Furthermore, Z. ovalifolia   is yellow to orange-yellow in the largest part of the lip, whereas in Z. agyokuana   it varies from white to pinkish white.

IBSC

South China Botanical Garden

A

Harvard University - Arnold Arboretum