Diplazium simplicivenium Holttum (1940: 100)

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 : 53

24. Diplazium simplicivenium Holttum (1940: 100) . Fig. 30 .

Type: MALAYSIA. Pahang, Holttum, R.E. 36507 (holotype SING!; isotype K000443625 !) .

Plants terrestrial. Stems massive, erect, 5–8 cm diameter, densely scaly at apex; scale 1.8–2.0 × 0.15–0.20 cm, linear, long tail at apex, brown, margin thick and toothed. Fronds 1.8–2.4 m, bipinnate; petioles 0.8–1.0 m, 1.5–2.0 diameter, deep green, densely scaly at base. Laminae 1.0–1.4 × 0.8–1.0 m, ovate–deltoid, terminal pinna not distinct; pinnae 6–8 pairs, alternate, 54–60 × 25–28 cm, stalked; stalk about 1 cm, oblong in outline, apex acuminate, glabrous, papyraceous, green; pinnules 12–14 pairs, alternate, 10–12 × 2.0– 2.5 cm, sessile, oblong, apex long acuminate, base truncate, margin shallowly lobed; lobes less than ¼ way to midrib of pinnules, 5–8 mm broad subquadrangular, apex obtuse, margin subentire; veins free, pinnate, 5–6 pairs of each vein group. Sori usually more than 5 mm long, elongate along veinlets, diplazoid, indusiate; indusia thin, firm, persistant. Spores monolete, 51.0–54.5 × 30.5–34.5 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: prominent wing folds.

Thailand: —NORTHERN: Chiang Mai (Doi Inthanon), Tak (Umm Phang);ESTERN: Nakhon Ratchasima (Sa Kaerat); SOUTH-WESTERN: Kanchanaburi (Khao Ngi Yai, Khao Yai, Thong Pha Phum), Uthai Thani (Ban Rai); SOUTH-EASTERN: Chon Buri (Khao Kiew); PENINSULAR: Surat Thani (Klong Ton), Nakhon Si Thammarat (Khao Luang, Khao Nan), Phangnga (Khao Pok), Trang (Khao Chong), Satun, Yala (Muang Wing) .

Distribution: — Myanmar, Malaysia Philippines and Indonesia.

Ecology: —On moist mountain slopes in dense evergreen forests at medium elevations at 400–1500 m elev.

Specimens Examined:— THAILAND. Kanchanaburi, Thong Pha Phum, A. Sathapattayanon 122 (BCU); Kanchanaburi, A.F. G. Kerr 10422 (BK); Satun, A.F. G. Kerr 10477 (BK); Trung, Khao, Chong, C. Apasutaya 122 (BCU); Trang, Khao Chong, C. Charoenphol, K. Larsen & E. Warncke 3707 (L); Kanchanaburi, Khao Yai, C.F. van Beusekom & C. Phengklai 290 (L); Uthai Thani, C.F. van Beusekom & T. Santisuk 2894 (L); no locality, C.F. van Beusekom & T. Santisuk 2894 (K); Chiang Mai, Doi Inthanon, E. Hennipman 3458 (BKF); ibis., E. Hennipman 3458 (B); Chon Buri, Khao kiew, J.F. Maxwell 75-665 (L); Chonburi, J.F. Maxwell 75-665 (BK); Trang, Khao Chong, M. tagawa & I. Yamada T 202 (L); Nakhon Si Thammarat, Khao Luang, M. Tagawa , K. Iwatsuki & N. Fukuoka T4803 (L); Chiang Mai, Doi Inthanon, P. Pongkai 94 (BCU); Nakhon Si Thammarat, Khao Luang, P. Pongkai 123 (BCU); ibis., P. Pongkai 95 (BCU); ibis., P. Pongkai 96 (BCU); Nakhon Ratchasima, Sa kaerat, T. Boonkerd 534 (BCU); Tak, Um Phang, T. Boonkerd 1848 (BCU); Nakhon Si Thammarat, Khao Nan, T. Boonkerd, S. Chantanaorapint & W. Khwaiphan 420 (BCU); Nakhon Si Thammarat, Khao nan, T. Boonkerd, Y. Sirichamorn & C. Sanguansab 151 (BCU); ibis., T. Boonkerd, Y. Sirichamorn & C. Sanguansab 208 (BCU); Trang, Khao Chong, T. Shimizu et al. T27456 (L); Kanchanaburi, T. Vongthavone 66 (BK); MYANMAR. Tenasserim Division, Tawer, J.F. Maxwell 98-327 (L); MALAYSIA. Pahang, A.G. Piggott 3116 (K); Selangor, B. Molesworth-Allen 4151 (K); Perak, B. Molesworth-Allen 4369 (K); Pahang, B.E.G.Molesworth-Allen 8329 (BM); Perak, Dr. King’s Collector 2214 (K); ibis., Dr. King’s Collector 2346 (K); ibis., Dr. King’s Collector 8420 (K); Perak, H.N. Ridley 12411 (K); Selangor, B. Molesworth-Allen, (K); Pahang, R. Jaman et al. RJ6011 (PE); Pahang, R.E. Holttum 36507 (K); ibis., R.E. Holttum SFN21636 (K); PHILIPPINES. Rizal, M. Ramos 956 (K); INDONESIA. Borneo, A.C. Jermy & J.M. Rankin J14840 (BM); Sumatra, J.A. Lörzing 15667 (K).

Figures

FIGURE 30. Diplazium simplicivenium Holttum. A, frond. B, a part of pinnule with sori. C, scale showing toothed and black marginal cells. P. Pongkai 94 (BCU).