马尾南星 ma wei nan xing

Arisaema hippocaudatum S. C. Chen & H. Li.

Rhizome oblique or horizontal, light brown outside, violaceous in section, cylindric, 3-6 × 2-3 cm. Cataphylls 3 or 4, grayish brown with purplish and black spots, longest one 10-15 cm, apex mucronate. Leaves 2; petiole green, marked with purple, to 30 cm, proximal 15-25 cm forming pseudostem; leaf blade 3-foliolate, paler and evidently veined abaxially, shiny green adaxially; central leaflet elliptic, 9.5-10 × 3.2-3.5 cm, aristate at apex, with a tip 8-11 mm; lateral ones slightly smaller. Peduncle erect, overtopping leaves. Spathe green tinged except for white center, ca. 12 cm, with proximal margins incurved or ± overlapping to form a cylindric tube to 6 × 2.7 cm, scarcely or slightly auriculate at throat; limb subovate-lanceolate, ca. 8 × 4 cm, apex aristate and recurved. Male spadix subsessile, ca. 16 cm; fertile zone green, subterete, gradually attenuate distally, ca. 4 cm, loosely flowered; male flowers stipitate, usually diandrous; stipe 0.2-0.9 mm; thecae ellipsoid, 0.4-0.7 mm; appendix extending beyond throat of spathe tube, recurved, greenish, horsetail-shaped, ca. 12 cm, with many filiform subulate neuter flowers; proximal neuter flowers scattered, 3-4 mm; distal ones numerous and crowded, 2.5-5.5 cm. Female spadix unknown. Fl. Jun.

Limestone crevices on hilltops; 600-700 m. Guangxi (Du’an) [Vietnam].

One of us (Murata) recognizes Arisaema hippocaudatum S. C. Chen & H. Li (Acta Bot. Yunnan. 24: 607. 2002) as a rare Chinese species known only from the type and A. victoriae as endemic to Vietnam. In A. victoriae, the main axis of the spadix appendix is distinct and much longer than the branches (neuter flowers) as in A. lihengianum, whereas in A. hippocaudatum, the main axis is not clear and (if still present) is of a similar size and shape to the branches in its distal part. On the other hand, one of us (Li) believes that the two entities are conspecific, based on observations of cultivated plants.