Diplazium mixtum (Roxb.) C.V. Morton (1974: 294)

Pongkai, Puttamon, Zhang, Li-Bing, Boonkerd, Thaweesakdi & Pollawatn, Rossarin, 2023, Revision of the fern genus Diplazium (Polypodiales: Athyriaceae) in Thailand, Phytotaxa 631 (1), pp. 1-69 : 32-35

14. Diplazium mixtum (Roxb.) C.V. Morton (1974: 294) . Fig. 17 .

Asplenium mixtum Roxburgh (1844: 499) .

TYPE: INDONESIA. Ambon ?, anon. s.n. ( C. Smith?) (lectotype BR [ BR0000006989866 ], designated by Morton (1974)) .

Asplenium prescottianum Wallich ex Hooker (1860: 251) . Diplazium prescottianum (Wall. ex Hook.) T. Moore (1859: 334) . Type : SINGAPORE. 1922, Wallich, 235 (lectotype K-W [ K001109599 ], designated by Morton (1974); isolectotypes K000443459 !, K000443460 !).

Plants terrestrial. Stems erect, 5–6 cm diameter, bearing thick black roots, apex scaly; scales about 15 × 1 mm, narrowly lanceolate, concolorous, dark brown, margin entire. Fronds up to 1.30 m, imparipinnate; petioles 60–80 cm, 5–6 mm diameter, glabrous, green with dark brownish base. Laminae 43–50 × 18–25 cm, outline oblong, suddenly becoming smaller upword, long acuminate apex, terminal pinna not distinct, glabrous, papyraceous, deep green; lateral pinnae 11–12 pairs, alternate, 13–17 × 1.7–2.0 cm, bolong, falcate, apex caudate-attenuate, base obtuse, margin crenate, moderately auricle at acroscopic base; aucicle, apex round to obtuse, margin subentire, stalked; stalk 2.0– 2.5cm, longest at lower pinnae; veins pinnate, veinlets 3–4 pairs. Sori 0.5–1.0 cm, elongate along veinlets, diplazoid, indusiate; indusia thin, firm, persistance. Spores monolete, 40.5–43.0 × 23.5–25.5 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: labryrinth.

Thailand: —SOUTH-EASTERN: Trat (Ko Chang) ; PENINSULAR: Nakhon Si Thamarat (Khao Luang), Yala

(Ban Chana, Ban Malao). Distribution: — Malaysia, Singapore. Ecology: — On humus-rich mountain slopes in dense evergreen forests at medium elevations. Specimens Examined :— THAILAND. Prachinburi, Khao Yai , K. larsen, T. Smitinand & E. Warncke 312 ( BKF) ; MALAYSIA. Perak, Anonymous s.n. ( K). SINGAPORE. Crangie, H. J. Murton 100 ( K); Tanjong Gul, J. Sinclair 9376 ( K); no locality, N. Wallich 235 ( K); ibis., T. Lobb 32 ( K).

Figures

FIGURE 17. Diplazium mixtum (Roxb.) C.V. Morton. A, frond. B, a part of pinna with sori. C, scale showing entire and not black marginal cells. J. Sinclair 9376 (SING).