Pinellia hunanensis C. L. Long & X. J. Wu, 2013

Liu, Yu-Jing, Newmaster, Steven G., Wu, Xian-Jin, Liu, Yue, Ragupathy, Subramanyam, Motley, Timothy & Long, Chun-Lin, 2013, Pinellia hunanensis (Araceae), a new species supported by morphometric analysis and DNA barcoding, Phytotaxa 130 (1), pp. 1-13 : 9

Pinellia hunanensis C. L. Long & X. J. Wu , sp. nov. ( Figs. 2 , 3)

Pinellia hunanensis differs from Pinellia ternata (Thunb.) Ten. ex Breitenb. in having very tall inflorescence, and long appendix.

Type: — CHINA. Hunan Province: Zhongfang County, Tongwan , cliff in moist forest in the valley, elev. 650 m, 6 July 2009, Long Chun-lin 113 (holotype: KUN!, isotype MUC!) .

Perennial aroid herb, 20 cm tall. Tuber globose, 1.5–3 cm in diameter. With one leaf, 18–22 cm long, with a green, unspotted petiole and nearly absent sheath. Bulbil at lower portion of petiole, 0.8–1.1 cm in diam. Leaf blades trisect or pentasect, leaflets with obvious petioles; central leaflet lanceolate, 16–20 cm long, 4–5.5 cm wide, upper side green, lower side silver-white, margin crisp; primary lateral veins of the leaf blade pinnate, forming a submarginal collective vein, 1 distinct marginal vein present, higher order venation reticulate; two lateral leaflets smaller, oblique at base. Young leaves simply cordate, 5–6 cm long, 3–4 cm wide. Inflorescence solitary, appearing with leaves, 45–55 cm long; peduncle green, much taller than petiole. Spathe persistent, 5–7.5 cm long, 0.4–0.7 cm in diameter, slightly constricted between tube and blade; tube 2–2.5 cm long, 0.4–0.5 cm in diameter, convolute, ellipsoid, almost closed inside by a transverse septum; limb of spathe oblong, fornicate, green, 3.5–5.5 cm long, much longer than tube. Spadix 12–15 cm long, longer than spathe, female zone 2–3 cm long, adnate to spathe, separated from the male zone by the spathe septum, and by the short, free, naked portion of spadix axis (0.9–1.4 cm long); male zone 1–1.5 com long, cylindric. Appendix smooth, erect or slight curve, elongate-linear, long-exserted from spathe, 8–12 cm long. Flowers unisexual, perigone absent. Male flowers 2-androus, stamens united congenitally in pairs, short, laterally compressed; anthers sessile, connective slender, thecae ellipsoid, 2-celled, dehiscing by apical slit; pollen extruded in amorphous mass, inaperturate, spherical, small, white. Female flowers with ovary ovoid-oblong, 1-locular; ovule 1, orthotropous, 2–2.5 mm long, 1.2–1.5 mm in diam., funicle very short; placentation basal, stylar region attenuate, stigma small, hemispheric.

Paratype: — CHINA. Hunan Province: Zhongfang Xian, Tongwan , on cliff within a moist forest in the valley, 670 m, 24 July 2009, Long 179 ( KUN!) . In the same valley on June 25 2011 at different altitudes: 580 m, Long 829 ( KUN!) ; 640 m, 834 ( KUN!) ; 650 m, 836 ( KUN!) .

Phenology: — Pinellia hunanensis starts to grow leaves in late April or early May, flowers in June-July, and fruits from mid-July to August. After August, the whole plant will get withered.

Etymology: —Named after Hunan Province where it was firstly discovered.

Habitat and distribution: —The new species was only found in Zhongfang County, western Hunan, Central China. It is restricted to wet cliffs in moist forests and is morphologically similar to Pinellia ternata , which does not grow on cliffs. There are subtle diagnostic characters that can be used to distinguish Pinellia hunanensis from P. ternata , such as the presence of only one leaf; a tall inflorescences up to 55 cm long, which is 2–3 times longer than petiole; long spadix axis; erect and very long appendix; three leaflets with a crisp, lanceolate margin; one large, central leaflet with two small lateral leaflets that are oblique at base ( Fig. 3, Table 2).

Figures

FIGURE 2. Pinellia hunanensis—A: habit; B: juvenile plant; C: leaf; D: inflorescence; E: spadix; F: infructescence; G: pistil; H: fruit; I: seed (Drawn after the holotype by Yitao Liu).