Diplazium simplicivenium Holttum

Family

Athyriaceae

Nomenclature

Diplazium simplicivenium Holttum, Gard. Bull. Straits Settlem. 11: 100. 1940; Tagawa & K.Iwats., SouthE. Asian Stud. 3(3): 88. 1965; Tagawa & K.Iwats., SouthE. Asian Stud. 5: 106. 1967; Tagawa & K.Iwats., Fl. Thailand 3: 464. 1988; Boonkerd & Pollawatn, Pterid. Thailand: 195. 2000. – Athyrium simplicivenium (Holttum) Holttum, Rev. Fl. Malaya ed. 1, 2: 573, f. 340. 1955 [‘1954’]; Holttum, Dansk Bot. Ark. 20: 32. 1961.

Description

Rhizome massive, erect, bearing a tuft of gigantic fronds; scales about 20 by 2 mm, brown, black-margined, toothed. Stipes up to 1 m long, about 2 cm diam. near base. Frond about 1.4 by 1 m, bipinnate; lower pinnae about 60 by 25 cm, narrowly oblong with acute apex; larger pinnules shortly stalked to sessile, narrowly subtriangular, gradually narrowing towards a acuminate apex, smaller ones rounded to acute, broadly cuneate to subtruncate or subcordate at base, usually shallowly lobed, up to 12 by 2.5 cm; lobes subquadrangular, obtuse at apex, subentire, 5–8 mm in breadth; softly papyraceous, green, shiny above; veins pinnate with 4–6 pairs of simple veinlets; veinlets hardly reaching the margin of lobes, basal anterior ones stopping far below the sinus. Sori about 8 mm long.

Distribution in Thailand

SOUTH-WESTERN: Uthai Thani, Kanchanaburi, Phetchaburi; SOUTH-EASTERN: Trat; PENINSULAR: Surat Thani, Phangnga, Nakhon Si Thammarat, Trang, Satun, Yala.

Wider Distribution

Peninsular Malaysia and probably also in Borneo.

Ecology

On moist mountain slopes in dense evergreen forests at medium elevations at 400–1500 m alt.

Similar species

Diplazium dilatatum Blume

Proposed IUCN Conservation Assessment

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

Habit

Habit

Pinnae

Pinnae

Lower surface of pinna

Lower surface of pinna

Young sori

Young sori

Young sori

Young sori

Mature sori

Mature sori

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