Malaxis malipoensis Y.F. Meng, A.Q. Hu & F.W. Xing, 2014

Meng, Yu-Fang, Hu, Ai-Qun, Yi, Qi-Fei & Xing, Fu-Wu, 2014, Malaxis malipoensis (Malaxideae: Orchidaceae), a new species from Yunnan, China, Phytotaxa 167 (2), pp. 195-200 : 195-198

Malaxis malipoensis Y.F. Meng, A.Q. Hu & F.W. Xing , sp. nov. ( Figs. 1 – 3 )

Type:— CHINA. Yunnan: Malipo , 1,900 m, under forest, 20 July 2012, Meng 20120130 (holotype: IBSC!, isotype: IBSC!) .

Species similar to Malaxis monophyllos ( L.) Sw. but differing in having smaller flowers, ovate sepals, sepal margin not revolute, and triangular lip without midlobe and a slightly notched column apex.

Terrestrial berbs or lithophytic, 5–15 cm tall including inflorescence. Pseudobulbs ovate, 0.4–0.6 × 0.6–0.8 cm. Leaf 1, ovate to oblong, base contracted to a petiole, 2–3 cm long, apex obtuse or subacute. Inflorescence arising from leaf axil, erect, up to 10 cm, pubescent; raceme 8 cm long, laxly 15-flowered; flower bracts oblong-lanceolate, green, ca. 2mm long. Flowers not resupinate, ca. 5 mm in diameter, yellowish green; pedicel and ovary 1.5–2.5 mm long. Sepals subequal, ovate to ovate-elliptic, spreading, ca. 1.63 × 0.85 mm, obtuse at apex, 1-veined; petals linear, 1.27 × 0.30 mm; lip uppermost in the flower, triangular in outline when expanded, 1.30 × 1.49 mm, disk oblate, slightly concave at base, margin thickened and verrucose, obtuse at the apex (without midlobe), base with a pair of auriculate lobes on each side (lateral lobes). Column ca. 0.8 mm long, slightly notched at the apex. Pollinia 4, waxy, in 2 pairs.

Palynology:— Pollinia 4, waxy, in 2 pairs, each pair perprolate, inaperturate. P / E ratio ca. 5, exine sculpturing is psilate. The outermost wall of the pollinium is thick and homogeneous, more or less with foveolae on the surface, less than 1 µm in diameter., Interior pollen grains lack a thick wall and are surrounded only by intine ( Fig. 4 ). These features of outer wall and interior pollen grain are the same as the description ( Zavada 1990) of those from M. paludosa ( L.) Swartz (1800: 235) and M. unifolia Michaux (1803: 157) .

Habitat and distribution:— Malaxis malipoensis is endemic to Yunnan, southwestern China; up to now it has only been collected at two localities: Malipo in Wenshan and Liangwang Mountain in Kunming, Yunnan ( Fig. 5 ). The new species usually grows in forests, thickets or shaded rocks, at 1,900–2,000 m .

Etymology:— The species epithet refers to the type locality where this species was first discovered.

Additional specimens examined (of related taxa):— Malaxis monophyllos (L.) Sw. CHINA. Hebei: Weixian, Xiaowutai Mountain , 2,400m, 9 July 1934, Wang 61618 ( PE) ; Sichuan: Emei Mountain, Jinding , 3,100m, 6 July 1937, Yu 7054 ( PE) ; Xizang: Linzhi, Nixi , 3,100m, 2 August 1965, Kaiyong 1255 ( PE) ; Jilin: Fusongxian, Man Jiang , 1,565m, 16 August, 1986, Hong et al. 33929 ( PE) ; Yunnan: Chungtian, Pica , 3,100m, 5 July 1937, Yu 11927 A ( PE) ; Qinghai: Tongdexian, Xiumaxiangjiang , 3,400m, 17 August 1990, Wu et al. 6875 ( PE)

Taxonomic Notes:— There are some similarities between Malaxis malipoensis and M. monophyllos , the latter widely distributed in temperate regions of Europe, Asia, and the Americas. Both have ovate or elliptic, conduplicate leaves, a triangular-ovate lip in outline, and auriculate inrolled lobes on the basal portion. However, Malaxis malipoensis differs in having smaller flowers, ovate to ovate-elliptic sepals, lip ca. 1.5 mm long, obtuse at apex, without midlobes, column slightly notched at the apex. In M. monophyllos , there is some variation in across its range. Margońska (2012) accepted the species Malaxis muscifera (Lindley, 1977: 105) Kuntze (1891: 673) but mentioned that it was difficult to distinguish it from M. monophyllos , whereas Chen et al. (2009) treated M. muscifera as a synonym of M. monophyllos . Davidson (1951) showed seven representative lip shapes with various lengths of M. monophyllos from different countries when he studied Malaxis species from North America, but all variation of the allied species, including M. muscifera , can be treated as variation within that species. All of them have linear-lanceolate sepals, an apex long acuminate with a revolute margin, lip 3–4mm long, with midlobe linear-lanceolate, constituting up to or more than 1/2 the lip length, and column with trilobed apex, all of which are different in Malaxis malipoensis .

Figures

FIGURE 1: Malaxis malipoensis. A. Habit. B–C. Flower, front and side views. D–E. Lateral sepals. F. Dorsal sepal. G. Lip. H–I. Petals. J–K. Column. L. Anther cap. M. Pollinia. Drawn from holotype by Yun-Xiao Liu.

FIGURE 2. Habitat and habit of Malaxis malipoensis (holotype locality). Photographed by Y. F. Meng.

FIGURE 3. Close-ups of inflorescence and single flower. A. Malaxis malipoensis (from type locality, photographed by Y.F. Meng). B. Malaxis monophyllos from Baihuashan Mountain, Beijing (photographed by Tian-Yi Yu).

FIGURE 4. Pollen morphology of Malaxis malipoensis. A. Pollinium. B. Exine sculpturing. C. Outermost thick wall. D. Interior of pollinium.

FIGURE 5. Distribution of Malaxis malipoensis in Yunnan, China.A. Malipo, Yunnan. B. Liangwang Mountain, Yunnan.