版纳南星 ban na nan xing

Plants evergreen. Rhizome yellowish outside, purplish inside, robust, 8-9 × 3-4 cm, rooting on whole surface and in different directions. Leaves 3-5 together, separately arranged on rhizome back, perhaps from different seasons; petiole pale green with dark green striae and whitish spots, or pinkish brown with black or dark brown short striae and sparse spots, cylindric, 28-60 × 0.4-2 cm, encircled by cataphylls; leaf blade pale green abaxially, green adaxially, subpapery, 3-foliolate; leaflets entire, base obtuse, apex acuminate with acumen 1-2 cm; central leaflet with petiolule 2.8-4.6 cm, blade green with scattered pale brown and black spots, elliptic to oblong, 14-24 × 6-10 cm, base cuneate to rounded; lateral leaflets with petiolule 5-10 mm, blade lanceolate, oblique, 12-24 × 4.5-10 cm, base obliquely rounded; cataphylls 2 or 3, colored as petiole, 5-20 cm. Peduncle encircled in cataphylls, colored as petiole, to 70 cm. Spathe green; tube 6-8 × 1.5-2 cm, throat margins spreading, auriculate; limb arching, obovate, ca. 5 × 3.5-4 cm, apex acuminate or acute. Spadix bisexual and unisexual (male). Bisexual spadix: female zone ca. 2 cm × 7 mm; ovary pale green, ovoid; style short; stigma pale white, disciform; male zone ca. 1.5 cm × 3 mm, sparsely covered by male flowers; appendix erect, greenish white, cylindric, ca. 3 cm × 1.5-3 mm, apex subclavate, verrucose to echinate. Male spadix: male zone ca. 6.7 cm, base ca. 6 mm in diam.; male flowers dense, of 2-4 stamens, subsessile; anthers violet to cream-yellow, ovoid or subglobose, dehiscing by an apical united slit; appendix cylindric, ca. 4.2 cm × 3 mm, base usually with some male flowers, apex subclavate, rugose, ca. 4 mm in diam. Berry orange-red, obovoid, ca. 5 × 4 mm. Fl. Feb-Mar, fr. Oct.

● Primary tropical rain forests; 700-1000 m. S Yunnan.

Arisaema bannaense is quite similar to A. garrettii Gagnepain, from Thailand. The species are possibly distinct only in the shape of the apical part of the spadix appendix. According to observations by Murata in S Yunnan, the appendix of A. bannaense is always subclavate, acuminate, and verrucate to muricate, and the apex is exserted from the spathe tube so that it is clearly seen from outside. In specimens examined by Murata, the appendix of A. garrettii is columnar, with a rounded apex, and equaling the spathe tube in length so that the apex is hardly seen from outside. The two taxa may be allopatric varieties.