Hypodematium crenatum (Forssk.) Kuhn

Family

Dryopteridaceae

Nomenclature

Hypodematium crenatum (Forssk.) Kuhn, Deck. Reis. Bot. 3: 37. 1879; Ching, Sunyatsenia 3: 9, f. 1. 1935; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 374, f. 32.3 & 32.4. 1941; Holttum, Rev. Fl. Malaya ed. 1, 2: 501, f. 295. 1955 [‘1954’]; Holttum, Dansk Bot. Ark. 23:238. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 106. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 437. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 197. 2000. – Polypodium crenatum Forssk., Fl. Aegypt. Arab.: 185. 1775. – Lastrea crenata (Forssk.) Bedd., Suppl. Ferns Brit. Ind.: 18. 1876; Bedd., Handb. Ferns Brit. India: 258. 1883.

Description

Rhizome short creeping, bearing close fronds, densely scaly; scales oblong-lanceolate, about 25 by 2.5 mm, concolorous, brown, entire. Stipes up to 50 cm long, green to stramineous, densely setose-hairy. Frond oblong-subdeltoid, widest at base, up to 55 by 45 cm, quadripinnatifid at basal pinnae; rachis deeply grooved, the grooves open at junction of costa; pinnae subtriangular, the upper ones gradually becoming smaller; ultimate segments oblong, adnate at base, moderately acute to subtruncate at apex, lobed with oblong, oblique lobes; softly papyraceous; veins pinnate, reaching the margin of lobes, all free; hairs dense on every part of frond, setose, about 5 mm long. Sori dorsal on veinlets, rather close to costules; indusia round-reniform or horse-shoe-shaped, about 1 mm broad, white to slightly greyish, margin entire, densely setose-hairy .

Distribution in Thailand

NORTHERN: Chiang Mai, Chiang Rai, Lampang; SOUTH-WESTERN: Kanchanaburi.

Wider Distribution

Throughout the warmer parts of the Old World S & E Africa, Cape Verde Islands, Mauritius, Arabia, N India, N Vietnam, S & Central China, Taiwan, Philippines, Peninsular Malaysia, Pacific Islands and as far north as Japan (subsp. fauriei).

Ecology

In crevices of rather moist limestone cliffs in mixed forests at medium to high altitudes.

Similar species

Tectaria tenerifrons (Hook.) Ching

Tectaria manilensis (C.Presl) Holttum

Proposed IUCN Conservation Assessment

Least Concern (LC). This species is widespread and not under any known threat.

Voucher specimens - Thailand

Middleton et al. 4985, Chiang Mai, Doi Chiang Dao Wildlife Sanctuary (E).

Habit

Habit

Habit

Habit

Rhizome

Rhizome

Rhizome

Rhizome

Rhizome

Rhizome

Base of stipe and scales

Base of stipe and scales

Frond

Frond

Rachis and bases of pinnae

Rachis and bases of pinnae

Lower surface of pinna

Lower surface of pinna

Lower surface of pinnules with sori

Lower surface of pinnules with sori

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.