Family

Osmundaceae

Nomenclature

Osmundastrum cinnamomeum (L.) C.Presl, Gefässbündel Farrn 18. 1847. – Osmunda cinnamomea L., Sp. Pl. 1066. 1753; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 32. 1939; Ching, Fl. Reipubl. Popularis Sin. 2: 80. 1959, with var. asiatica and var. fokiense; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 33. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 45. 1979; Boonkerd & Pollawatn, Pterid. Thailand: 31, 77. 2000.

Description

Fronds congested at apex of rhizome, dimorphic; young fronds covered with reddish brown hairs. Sterile fronds yellowish green, covered densely with downy hairs when young but glabrescent in adult form; stipes about 40 cm long, stramineous; laminae bipinnatifid, lanceolate, gradually narrowing towards acute apex, one or two basal pinnae slightly short and deflexed, 50–60 cm long, about 12 cm wide; lateral pinnae with the angle of 60° to rachis, nearly straight, deeply pinnatifid, acute at apex, cordate at sessile base, linear-lanceolate, 6–8 cm long, up to 1.5 cm wide; ultimate segments oblong, oblique, round at apex, entire, up to 8 mm long, 5 mm broad, glabrous. Fertile fronds shorter, soon fading after the maturation of sori .

Distribution in Thailand

NORTH-EASTERN: Loei.

Wider Distribution

Eastern N America, E Asia south to Vietnam and Upper Burma.

Ecology

Terrestrial on wet sandy ground by streams in open grassy areas at about 1200 m alt.

Proposed IUCN Conservation Assessment

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

Notes

Use. – Fibrous roots esteemed for orchid cultivation.

Notes. – The Asiatic plants are different from the American ones in having blackish hairs mixed with whitish ones at the base of the fertile fronds, but this is not adequate to separate the Asiatic plants as a different variety .