Heterogonium hennipmanii Tagawa & K.Iwats.

Family

Tectariaceae

Nomenclature

Heterogonium hennipmanii Tagawa & K.Iwats, Acta Phytotax. Geobot. 26: 59, f. 15. 1974; Holttum, Kalikasan 4: 216. 1975; Tagawa & K.Iwats., Fl. Thailand 3: 362. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 206. 2000. – Type: Hennipman 3060 (L), Thailand, Tak, Doi Musoe.

Description

Frond subdimorphic. Sterile frond: stipe about 35 cm long, dark brown to castaneous, scaly near base; scales oblong, gradually narrowing towards tailed apex, dark brown to nearly black, hairy, more than 1 cm by up to 2 mm. Laminae oblong-lanceolate, pinnate with deeply lobed pinnae, up to 35 cm wide near base; lateral pinnae sessile or very shortly stalked in basal ones, mostly straight and ascending, broadest in middle, gradually narrowing towards attenuate apex, up to 20 by 3.2 cm, ultimate segments broadly oblong, oblique, a little falcate, rounded at apex, subentire or minutely waved at margin, up to 12 by 7 mm; papyraceous, dark green; veins in segments simple or forked. Fertile frond: stipe up to 30 cm long; lamina oblong-lanceolate, pinnate with deeply lobed pinnae, up to 60 by 25 cm; segments oblong, oblique to subquadrangular, rounded to obtuse at apex, subentire to dentate. Sori dorsal on veinlets, medial, round, indusiate; indusia round-reniform, thin, fugacious .

Distribution in Thailand

NORTHERN: Tak.

Wider Distribution

Endemic to Thailand.

Ecology

Moist evergreen forests along streamlets, c. 800 m alt.

Proposed IUCN Conservation Assessment

Critically Endangered CR B1ab(iii).  This species is only known from Doi Musoe in Tak province.  The area of occupancy is uncertain but the extent of occurrence is clearly less than 100 km2.  Doi Musoe is very disturbed through development projects.  There is a possibility this species may also occur in the nearby Taksin and Lansang National Parks but until it is found there it must be considered to be critically enadangered.

Site hosted by the Royal Botanic Garden Edinburgh. Content managed by Stuart Lindsay, Gardens by the Bay, Singapore and David Middleton, Singapore Botanic Gardens. Last updated 16 November 2016.