Arisaema anatinum Brugg., 2018

Bruggeman, P., 2018, Arisaema anatinum, a new species of Arisaema (Araceae) from NE India, Blumea 63 (2), pp. 147-149 : 147-149

publication ID

https://doi.org/10.3767/blumea.2018.63.02.11

persistent identifier

https://treatment.plazi.org/id/03A887B5-CE63-FFF7-0005-1BB9B5C4FE31

treatment provided by

Felipe

scientific name

Arisaema anatinum Brugg.
status

sp. nov.

Arisaema anatinum Brugg. View in CoL , sp. nov. — Plate 1 View Plate 1

Most closely allied to A. elephas , A. wilsonii and A. dilatatum but differing in having a convolute, oblong spathe blade, broadly ovate, shiny leaflets and a non-sigmoid appendix. — Type: M. Bhaumik 2502 (holo CAL), India, Arunachal Pradesh State, Lower Dibang District, Mayodia , 2690 m a.s.l., 21 Apr. 1999 ; P. Bruggeman PBR749 (para L, male and female in spirit, prepared from cult.)

Etymology. The species epithet, from the Latin adjective anatinus, of, or resembling a duck, refers to the bill-shaped spathe blade.

Seasonally dormant geophyte, up to 120 cm tall. Subterranean stem depressed globose tuber, up to 12 cm diam with numerous dormant offsets. Roots white, branching with short feeding roots. Pseudostem absent or inconspicuous. Cataphylls 2 or 3, up to 15 cm long, striated. Leaves 2 or 3, often with a reddish rim and strong yellow venation, dark to olive green with occasionally dark blotches that fade during the season. Petiole up to 80 cm long, up to 20 mm wide at base, 4–5 mm wide at the top, uniformly green, glabrous. Blade trifoliolate, central leaflet broad obovate, 20–30 cm long, 5–7 cm wide, sessile to subsessile. Lateral leaflets elliptic-ovate to broad-ovate, approximately the same length as central leaflet, to 30 cm long, 6–8 cm wide, sessile to subsessile, leaflets often overlapping each other. Inflorescence held beneath the leaves at anthesis. Peduncle 10 cm long, green, elongating up to one meter tall when fruiting. Spathe tube green to olive green with translucent veins, often glaucous on the outer surface, cylindrical, strongly ribbed inside, 10–15 cm long, 2.5–3 cm diam. Margins of spathe mouth revolute becoming strongly revolute along the spathe blade. Spathe blade horizontal, oblong to truncate, abruptly narrowing towards the tip into a short acumen, green to green-purple or red outside, revolute at margins. After pollination spathe remaining intact and shielding developing infructescence until berries ripen. Spadix unisexual. Male spadix fertile zone 3.5 cm long and c. 1 cm across at base, stipe 3 mm long. Synandria densely arranged, beige, 3- or 4-androus, thecae dehiscent by a horseshoe-shaped slit, pollen white. Female spadix fertile zone 4 cm long and 2 cm across. Pistils densely arranged. Ovaries ovoid, green, striped purple, 2–2.5 mm wide, stigma sessile, white, stipe 5 mm long. Spadix appendix 8 mm across at base, up to 25 cm long, pendent, gradually tapering, often distally contorted.

Phenology — Flowering: April, May; fruiting: September, October.

Distribution & Ecology — Arunachal Pradesh and Bhutan, growing in shaded, forested areas or on the edges of bamboo thickets in moist, humus rich soil at altitudes of 2300–3300 m a.s.l. In Arunachal Pradesh Arisaema anatinum has been observed in Lower Dibang and Upper Siang districts by the author and in West Kameng by John Roy (pers. comm.). In SE Bhutan is has been observed in the Trashigang District by Johan Nilson of Gothenburg Botanic Garden (pers. comm.). Thus far it has not been reported from Tibet but given the currently known distribution, its occurrence there cannot be excluded.

M

Botanische Staatssammlung München

CAL

Botanical Survey of India

Kingdom

Plantae

Phylum

Tracheophyta

Class

Liliopsida

Order

Alismatales

Family

Araceae

Genus

Arisaema

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