Davallia heterophylla Sm.

Family

Davalliaceae

Nomenclature

Davallia heterophylla Sm., Mém. Acad. Roy. Sci. (Turin) 5: 415. 1793; Tagawa & K.Iwats., Fl. Thailand 3: 616. 1989; Nooteboom, Fl. Males., Ser. II, Ferns and Fern Allies 3: 254. 1998. – Humata heterophylla (Sm.) Desv., Mém. Soc. Linn. Paris 6(3): 323. 1827; Bedd, Handb. Ferns Brit. India: 46. 1883; Bonap., Notes Ptérid. 14: 53. 1923; E.Smith, J. Siam Soc. Nat. Hist. Suppl. 8: 2. 1929; Tardieu & C.Chr., Fl. Indo-Chine 7(2): 109. 1939; Holttum, Rev. Fl. Malaya ed. 1, 2: 366, f. 211. 1955 [‘1954’]; Tagawa & K.Iwats., Fl. Thailand 3: 168. 1985; Boonkerd & Pollawatn, Pterid. Thailand: 171, 235. 2000. – Type: Charles Miller 1778 (BM).

Description

Rhizome long creeping, about 1.5 mm diam., bearing dimorphic fronds remotely, glaucous, densely scaly; scales gradually narrowing from oblong base towards long tails, up to 6 by 0.7 mm, tails usually patent, brown to darker, minutely toothed. Sterile frond: stipe 0.5–2.5 cm long, narrowly winged; lamina simple, oblong, acuminate at apex, round to cuneate at base, entire, 6–9 by 2–2.5 cm; coriaceous, naked; veins twice or thrice forked, all free. Fertile frond: stipe 1–2.5 cm long, winged; lamina linear-lanceolate, gradually narrowing towards both ends, up to 9 by 1 cm, lobed to half way; lobes patent, round, wavy. Sori terminal on veinlets, 3–5 for each lobe, a little inside the edges; indusia up to 1 mm long, 2 mm broad, brown, entire .

Distribution in Thailand

PENINSULAR: Surat Thani, Phangnga, Krabi, Nakhon Si Thammarat, Songkhla, Narathiwat.

Wider Distribution

Throughout Malesia to the Pacific, north to S Vietnam (“Cochinchina”).

Ecology

On branches of trees in dense forests.

Proposed IUCN Conservation Assessment

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

Voucher specimens - Thailand

Middleton et al. 5224, Songkhla, Ton Nga Chang Wildlife Sanctuary (E).

Habit

Habit

Habit

Habit

Habit

Habit

Habit

Habit

Rhizome

Rhizome

Sterile and fertile fronds

Sterile and fertile fronds

Fertile and sterile fronds

Fertile and sterile fronds

Variation from sterile (margin entire) to fertile fronds (margin lobed) and intermediate stages

Variation from sterile (margin entire) to fertile fronds (margin lobed) and intermediate stages

Sterile fronds

Sterile fronds

Upper surface of fertile frond

Upper surface of fertile frond

Lower surface of fertile frond

Lower surface of fertile frond

Sori

Sori

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