Arisaema menglaense Y.H.Ji, H.Li & Z.F.Xu

Plants perennial, evergreen, monoecious or male. Rhizome erect, light brown outside, violaceous in section, oblique or horizontal, cylindric, 5–6 × 2.5–3cm, with numerous nodes bearing buds, roots 10–15cm. Pseudostem absent. Cataphylls 5, flesh-colored, 5–8 × 1.5–2cm, membranous, 2 encircling petiole and peduncle, 3 enclosing peduncle directly. Leaves 1 or 2, arising at different seasons from different rhizome nodes; petiole viridescent with inconspicuous white spots, cylindric, ca. 45cm × 5–8mm; leaf blade green, 3-foliolate; central leaflet with petiolule ca. 1.7cm, blade elliptic, ca. 21 × 11cm, base cuneate, apex acuminate with acumen ca. 1cm; lateral leaflets with petiolule ca. 1.5 cm, blade obliquely broadly lanceolate, ca. 20 × 8cm, base broadly cuneate, apex acuminate with acumen 0.9–1cm; lateral veins 7–9 on each side, collective vein 4–9mm from margin. Peduncle green, cylindric, shorter than petioles, ca. 20 × 0.5cm. Spathe green, with numerous longitudinal veins; tube funnel-shaped, ca. 7 × 1.5–3cm, throat margin recurved to 8mm wide; limb bent forward, oblong, ca. 6.5 × 4cm. Bisexual spadix ca. 3.5cm; female zone ca. 1.5cm; female flowers densely arranged; ovary greenish, obovoid, ca. 2.5 × 1–2mm; ovules 4, erect; male zone ca. 2cm; synandria sparse; synandria of 2 or 3 fused stamens; stalk ca. 2mm; anthers 3, each comprising 2 thecae; thecae subglobose, ca. 1mm in diam., dehiscing by an apical slit; appendix sessile, erect, proximally purple, distally green, ca. 5.5cm × 1–4mm, usually exserted from spathe tube by ca. 1cm, wholly covered by filiform neuter flowers; neuter flowers erect, green, 5–10mm. Male spadix ca. 3cm × 2mm; appendix ca. 5cm.