Diplazium leptophyllum Christ ex C. Christensen (1913: 106)

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 : 29

11. Diplazium leptophyllum Christ ex C. Christensen (1913: 106) . Fig. 14 .

Type: CHINA. Yunnan, Szemao , A. Henry 13106 (lectotype MO-2140172 / A: 1194 !; designated here; isolectotype K00189421 !, MO-255735 / A: 1195 !, P01564505 !!) .

Plants terrestrial. Stems short creeping, 1.0– 1.5 cm diameter, scaly; scales 10–12 × 1.0– 1.5 mm, linear, concolorus, dark brown to nearly black, margin entire. Fronds up to 1.20 m, bipinnate to bipinnate-tripinnatifid; petioles 30–50 cm, glabrous, dark green, dark at lower portion, groove above. Laminae 60–70 × 50–60 cm, subdeltoid in outline, terminal pinna not distinct, glabrous, papyraceous, light green; pinnae 6–8 pairs, alternate, 25–30 × 12–15 cm, oblong in outline, apex acuminate, stalked; stalks 1.5–2.0 cm; pinnule 12–14 pairs, alternate, 5–6 × 2.5–3.0 cm, subdeltoid, apex acuminate, base subtruncate to truncate; lobed at margin; lobes ¾ way to costule, apex round, margin serrate, shortly stalked; veins pinnate, veinlets 4–5 pairs, free, simple or once forked. Sori 3–5 mm, elongate along veinlets, diplazoid, usually on basal veinlets of vein group. Spores monolete, 30.0–37.5 × 17.5–20.0 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: echinate.

Thailand: —NORTHERN: Chiang Mai (Doi Chiang Dao, Doi Suthep, Mae Jam), Chiang Rai (Mae Lao), Lamphun (Doi Khun Tan) .

Distribution: — India, Bhutan, China and Myanmar.

Ecology: —On moist ground or on mountain slopes in dense mixed or evergreen forests at 850–1,600 m elev.

Specimens Examined:— THAILAND. Chiang Mai, Doi Suthep, J.F. Maxwell 89-855 (L); Lampoon, Doi Khun Dan, J.F. Maxwell 93-771 (L); Chiang Mai, Mae Jam, J.F. Maxwell 98-1444 (L); Chiang Mai, Chiang Dao, M. Shimizu & M Hutoh T4396 (L); ibis., M. Shimizu & M Hutoh T10210 (L); ibis., M. Shimizu & M Hutoh T10210 (BKF); Chiang Mai, Chiang Dao, M. Tagawa & K. Iwatsuki T4396 (BKF); Lamphun, Doi Khun Tan, M. Tagawa T9324 (L); Chiang Mai, Chiang Dao, P. Pongkai 78 (BCU); ibis., P. Pongkai 79 (BCU); ibis., P. Pongkai 80 (BCU); Chiang Mai, Doi Suthep, S. Premwichit 5 (L). CHINA. Yunnan, A. Henry 13106 (B, K). INDIA. Manickam RHT34384 (K); Manickam 31083 (K); Manickam 582 (K).

Figures

FIGURE 14. Diplazium leptophyllum Christ. A, pinna. B, a part of pinnule with sori. C, scale showing entire and black marginal cells. P. Pongkai 79 (BCU).