Diplazium fraxinifolium C. Presl (1825: 49)

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 : 24

8. Diplazium fraxinifolium C. Presl (1825: 49) . Fig. 11 .

Type: THE PHILIPPINES. Hab. in insula Luzon, T.P.X. Haenke s.n. (lectotype PRC450306 !; designated by Hovenkamp 2019: 62; isolectotype PRC450305 !) .

Diplazium riparium Holttum (1940: 97) . Type: MALAYSIA. Selangor, Semenyih, Hume 8186 (holotype Federated Malay States Museums in SING 0069600 !).

Plants terrestrial. Stems erect, 1.5–2.0 cm diameter, bearing wiry roots, apex scaly; scales up to 17 × 1.0– 1.5 mm, linear with long tail, concolorous, dark brown to nearly black, margin entire. Fronds 55–80 cm, imparipinnate; petioles 42–50 cm, 4–7 mm diameters, green when living, stramineous when dry, black at lower portion, scaly at base. Laminae 25–30 × 21–25 cm, ovate-oblong in outline, terminal pinna distinct like lateral one, glabrous, subcoriaceous, light green; lateral pinnae 2–4 pairs, subopposite to alternate, 15–20 × 3–5 cm, oblong, sessile or very short-stalked, apex acuminate, base acute, margin entire or subentire; veins rarely anastomosing. Sori 1.0– 1.5 cm, elongate along veins, often on every veinlet, longest on acrocsopic veinlets of vein group. Spores monolete, 42.5–50.0 × 25–30 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation prominent wing folds.

Thailand: —PENINSULAR: Chumphon (Langsuan); Nakhon Si Thammarat (Khao Luang, Khao Nan, Groong Ching waterfalls, Ronpibun); Surat Thani (Tako, Ban Don); Trang ( Khao Chong ); Satun; Songkhla (Ton Nga Chang waterfalls); Yala (Ban Chana).

Distribution: — Malaysia, Philippines, Brunei, Indonesia and Singapore.

Ecology: —On muddy rocks or on earth by streams in dense forests at low elevations.

Specimens Examined:— THAILAND. Nakhon Si Thammarat, Khao Luang, B. Sangkachun 16024 (K); Trung, C. Apasuthaya 126 (BCU); Nakhon Si Thammarat, Groong Ching waterfalls, D.J. Middleton et al. 5531 (PSU); Pattani, Ban Chauaka, E. Smith 1920 (K); Satun, E. Smith 2628 (BM, K); Bandon, E. Smith 2630 (K); Satun, E. Smith 2631 (K); Nakhon Si Thammarat, Ronpibun, E. Smith 415 (K); Trang, Khao Chong, J.F. Maxwell 85-675 (L); Trang, Khao Chong, J.F. Maxwell 85-975 (PSU); Nakhon Si Thammarat, Groong Ching waterfalls, J.F. Maxwell 86-573 (L, PSU); Songkhla, Ton Nga Chang waterfalls, N. Putthisawong 67 (PSU); Nakhon Si Thammarat, Groong Ching waterfalls, P. Pongkai 45 (BCU); ibis., P. Pongkai 48 (BCU); Chumphon, Langsuan, Put 1659 (K); no locality, Put 1689 (BM); Chumphon, Langsuan, Put 1689 (BK); no locality, Sangkachun 16024 (K); no locality, T. Seelanan 3 (BCU); Nakhon Si Thammarat, Groong Ching waterfalls, W. Klinla-ang et al. 2 (PSU). BRUNEI. Temburong, A.D. Poulsen 123 (K); Arboretum, Sg. Liang, D.S. Edwards 478 (BM); Temburong, K.M. Wong 854 (K). INDONESIA. Java, A. MacLeay s.n. (K); Sulawesi, D. Hicks 208 (K); Borneo, J.W. Prout s.n. (K); Kalimantan, K. Iwatsuki, M. Kato, G. Murata & Y.P. Mogea B3204 (K); ibis., K. Iwatsuki, M. Kato, G. Murata & Y.P. Mogea B586 (K); Kalimantan, M. Kato & H. Wiriadinata B6222 (K); Seram, M. Kato, K. Ueda & U.W. Mahjar C1668 (K); Kalimantan, M. Kato, M. Okamoto, K. Ueda & D. Darnaedi B8126 (K). MALAYSIA. Sarawak, J.A.R. Anderson & H. Keng 24 (K), ibis., J.A.R. Anderson & H. Keng K96 (K); Pahang, A. Samat bin Abdullah 229 (K); ibis., A. Samat bin Abdullah 912 (K); Malacca, A. Sinclair s.n. (K); Selangor, A.G. Piggott 2878 (K); Perak, B. Molesworth-Allen 2733 (K); Selangor, B.E.G. Molesworth-Allen 2359 (BM); Pahang, B.S. Parris & P.J. Edwards 10414 (K); Sarawak, B.S. Parris 6961 (K); Sabah, D. Soibeh 659 (K); Johore Gunong Panti, Dr. King’s Collector 235 (K); Perak, Dr. King’s Collector 7894 (K); Malacca, H.N. Ridley 10786 (K); Kelantan Ulu Sungei Keteh, M. Nur s.n. (K); Sarawak, Native Collector (K); Sabah, P.J. Edwards 2042A (K); Pahang, R.E. Holltum SFN20792 (K); ibis., R.E. Holltum SFN24780 (K), no nocality, T. Lobb s.n. (K). PHILIPPINES. Luzon, H.G. Gutierrez 78330 (K); Sulu Archipelago, Y. Kondo & G. Edaño 38694 (K). SINGAPORE. no locality, T. Lobb 33 (K).

Note:—This species is similar to Diplazium bantamense , but different in having concolorous scales. Scales are entire at margin with caducous membrane. Venation of D. fraxinifolium is rarely anastomosing. Moreover, this species is different from the imparipinnate form of D. cordifolium in having oblong pinnae. Sori of this species are usually on acroscopic veinlets of the vein group.

Figures

FIGURE 11. Diplazium fraxinifolium C.Presl. A, whole plant.B, a part of pinna with sori. C, scale showing entire and not black marginal cells. P. Pongkai 45 (BCU).