|Asplenium minutifolium Kanem. & Tagane|
A new species of Asplenium (Aspleniaceae), Asplenium minutifolium Kanem. & Tagane, from Phu Kradueng National Park, Loei Province, Northeast Thailand and Khao Yai National Park, Nakhon Nayok Province, Central Thailand, is described and illustrated. This species can be distinguished from all similar species in East and South-East Asia by its simple and small lamina (1–5 × 0.3–0.7 cm), small and entire pinnae (1–4 × 0.8–2.5 mm), reflexed pinna arrangement (>90° from the midrib) in the lower 2/3 of the lamina and a sori arrangement that is almost always arranged in a single row on the basiscopic vein.
KEYWORDS: Asplenium, Aspleniaceae, Pteridophyte, Fern, new species, Phu Kradueng National Park, Khao Yai National Park, Thailand.
|Figure 2. Asplenium minutifolium Kanem. & Tagane, sp. nov.|
A. habit; B. portion of lamina (undersurface) showing sori; C. rhizome with scales; D. habitat.
Asplenium minutifolium Kanem. & Tagane, sp. nov.
Similar to Asplenium kiangsuense Ching & Y.X.Jing of southern China in size and shape of lamina, but differs in having a narrower lamina (ca 0.7 cm wide in A. minutifolium vs. ca 1 cm wide in A. kiangsuense), wingless rachis (vs. 2 slightly raised lateral wings), smaller pinnae (1–4 × 0.8–2.5 mm vs. 4–5 × 4–5 mm), generally fewer sori per pinna (1– 3(–4) vs. 3–5), and in the sori arrangement (usually arranged in a row vs. arranged oppositely). Also similar to Asplenium siamense Tagawa & K.Iwats. of North-East Thailand, but can be distinguished by its simple pinnae at the tip of lamina (vs. lamina forked several times at the tip), thicker pinnae (thickly papery vs. thinly papery), reflexed pinna arrangement in lower part (vs. divaricate around lamina), and pinnae with entire or slightly undulate margins (vs. shallowly lobed (lobes to ca 1mm long)).
–– Type: Thailand. Loei Province, Phu Kradueng National Park, Lom Sak Cliff, alt. 1292 m, 12 June 2015, Kanemitsu et al. T4736 (holotype BKF!, isotype TNS!).
Distribution.–– Currently Asplenium minutifolium is known only from Phu Kradueng National Park and Khao Yai National Park.
Ecology.–– In Phu Kradueng National Park, Asplenium minutifolium occurs in a semi-shaded and damp rock crevice that is ca 50 cm wide and 10 cm deep, on the plateau at an altitude of ca 1300 m. Associated fern and lycophyte species include Aglaomorpha rigidula (Sw.) Hovenkamp & S.Linds., Goniophlebium subauriculatum (Blume) C.Presl, Oleandra undulata (Willd.) Ching, Pyrrosia lingua (Thunb.) Farw. var. heteractis (Mett. ex Kuhn) Hovenkamp, and Selaginella siamensis Hieron. Other than the elevation, nothing is known about the ecology of this species at Khao Yai National Park.
Etymology.–– The species epithet “minutifolium” refers to the very small lamina and pinnae of this species.
Hironobu Kanemitsu, Shuichiro Tagane, Somran Suddee, Sukid Ruangruaea, Tetsukazu Yahara. 2017. Asplenium minutifolium (Aspleniaceae), A New Species from Thailand. THAI FOREST BULL., BOT. 45(1); 29–34. DOI: 10.20531/tfb.2017.45.1.06