Glyptopetalum verticillatum Q. R. Liu & S. Y. Meng, 2015

Liu, Quanru, Meng, Shiyong, Xu, Dongxian, Wang, Jinglan & Wang, Shan, 2015, Glyptopetalum verticillatum (Celastraceae), a new species from Yunnan, China, Phytotaxa 234 (2), pp. 186-190 : 186-189

Glyptopetalum verticillatum Q. R. Liu & S. Y. Meng sp. nov.

Type: — CHINA. Yunnan province: Yuanjiang county, Dashuiping, alt. 795 m, 23°33’45.4”N, 101°56’41.8”E, 10 July 2011, Q. R. Liu

201107018 (holotype BNU! Barcode No. BNU 0015315, isotype BNU (6 sheets)! CSH (1 sheet)! PE (1 sheet)!). Figures 1 & 2 . Additional specimens examined: — CHINA. Yunnan: Yuanjiang, Dashuiping, Q. R. Liu 201010048 ( BNU!), 20110317001 ( BNU!), 201107007 ( BNU!), 201107017 ( BNU!), 201107019 ( BNU!), 201107020 ( BNU!), 201203001 ( BNU!), 2012030907 ( BNU!), 2012030908 ( BNU!), 20130301 ( BNU!), 20130302 ( BNU!), 20130303 ( BNU!), 201403012 ( BNU!), 201403013 ( BNU!), 201403014 ( BNU!), 201403015 ( BNU!); S. Y. Meng 08004 ( BNU!), 0904061 ( BNU!); G. D. Tao 38785 ( HITBC!, KUN!), 38065 ( HITBC!, KUN!), 38206 ( HITBC!, KUN!); S. Wang & Q. R. Liu, 201203001 ( BNU!); Yunnan: Mengla, Menglun, Xishuangbanna Tropical Botanical Garden, cult. C. Du DC00141 ( CSH!). Species affinis Glyptopetalo continentalo (Chun & F. C. How) C. Y. Cheng & Q. S. Ma, a qua differt foliis 3 – 5, verticillatis vel rarissime oppositis, foliis furvo-viridibus, apice leviter obtusis, fructibus 0.7–1.1 cm diam., seminibus 1/3–1/4 arillis circumdatis. Glyptopetalum verticillatum is similar to G. continentale (Chun & F. C. How) C. Y. Cheng & Q. S. Ma , but differs in that it has whorled leaves that are dark green with a slightly obtuse apex, fruits of 0.7–1.1 cm in diam. and ca. 1/3–1/4 of seeds covered by aril.

Evergreen shrubs, 1–3 m tall; bark grown, coarse; branchlet sturdy, green when young, terete, internodes 3–10 cm long. Leaves in whorls of 3–5, occasionally opposite on the old twigs; petioles short and sturdy, 2–5 mm long; blades thickly leathery, oblong or ovate-oblong, 6–17.5 cm × 3–7 cm, adaxially dark green, abaxially jade-green, base broadly cuneate or rounded, apex short acuminate or obtuse; margin crenulate, usually crispate after dried; midrib obvious on both surface, lateral veins 5–9 pairs, slender and both surfaces plane, obvious. Inflorescences 2.5–5 cm long, pedicel ca. 1.5 cm long. Cymes axillary, density, 2–3 dichotomously branched. Flowers yellow-green, 8–10 mm in diam.; petals 4, triangle, 4 mm long; stamens 4, inserted at the angles of the disk, filaments short. Ovary immersed in the disc, 4-lobed, 1-ovule in one cell. Capsules subglobose, 0.7 ‒ 1.1 cm in diam., pericarp white, very thick and rigid, rough with minute tubercles. Seeds red, globose, anatropous, 0.6 × 0.4 cm; aril helmet, crimson when dry, covering ca. 1/4–1/3 of seed, raphe 4–6 branched.

Distribution and habitat: — Yunnan province, China. Other species growing in association with G. verticillatum are Cipadessa baccifera (Roth 1821: 215) Miquel (1868:6) , Dalbergia sp. , Colona sp. , Helicteres angustifolia (Linneaus 1753: 963) , Millettia sp. , Rubus sp. , etc.

Ecology: —elev. from 650 m to 850 m of the valley side.

Phenology: —Flowers and fruits were collected in early March and July.

Etymology: —The specific epithet refers to its verticillate phyllotaxy, which is particular to the family Celastraceae .

Palynology: —The pollen grains of the new species are spheroidal, with P= 16.875 nm and E= 14.906 nm (P/E=1.132), 3- colporate apertures and a reticulate tectum ( Fig. 3 ). The pollen characters are congruent with previously observed congeneric species ( Meng 2010, Wang 2013).

IUCN-conservation status: — After several botanical surveys of Yunnan province during 2010 ‒ 2014, we found only 32 adult individuals of this newly identified species in 2 populations. All specimens of the genus Glyptopetalum from China and its online specimen images have been examined, and no other material of this newly identified species was found. Furthermore, all collections were performed in unprotected areas near villages ; thus, this species may potentially be disturbed by human activities. Therefore, it is suggested that the status of this species is critically endangered: CR B1 ab (i, ii, iii, v), according to the IUCN Red List Categories and Criteria (2003) .

Discussion: —This species was first collected by G. D. Tao (G. D. Tao 38206, HITBC) and was identified as “ Glyptopetalum sp. ”. When specimens of this genus in the HITBC were examined, we found that its young fruit is characteristic of the genus Glyptopetalum and, thus, that this plant may be a new species in that genus. Luckily, when we collected specimens at Dashuiping, Yuanjiang county, Yunnan province (the same location as the specimens in the HITBC), we found living individuals of this new species. After performing fieldwork and a literature review, we were confident that it is an undescribed species with verticillate leaves, which is unique in the genus Glyptopetalum .

Glyptopetalum verticillatum is similar to G. continentale (Chun & F. C. How 1958: 50) C. Y. Cheng & Q. S. Ma (1999: 92) . After examination of specimens and the literature, the latter species was confirmed as an independent species (Cheng, & Ma, 1999; Meng, 2011). Liu & Funston (2008) wrongly considered this species to be G. longipedicellatum . Both species have thickly coriaceous and oblong or ovate-oblong leaves, green-yellow flowers, red seeds and red arils; however, G. verticillatum can easily be distinguished by its verticillate (versus opposite) and more dark green (versus light green) leaves, a slightly obtuse (versus acute) apex, smaller fruit (0.7 ‒ 1.1 cm versus 1.5 cm) and 1/3–1/4 (versus more than 1/2) seed coverage by aril. Our preliminary phylogeny results suggest that this species is sister to G. continentale (Wang, 2011) . Because of its particular phyllotaxy, this species may provide information about the phylogeny of the genus Glyptopetalum .

Figures

FIGURE 1. Glyptopetalum verticillatum. A. Habit; B. Verticillate leaves; C. Infructescences; D. Fruits; E. Flowers; F. Seed; G. Aril.

FIGURE 2. Glyptopetalum verticillatum. A. Fruiting branch; B. Stamen; C. Flower; D. Seed; E. Aril. (Drawings by Q. R. Liu from the holotype except B and C.)

FIGURE 3. Pollen Morphology of Glyptopetalum verticillatum.