Sphaerostephanos heterocarpus
Content
Distribution
Asia-Temperate: China Southeast (Hong Kong present); Hainan (Hainan present), Asia-Tropical, New Hebrides present, North Queensland present, Pacific: Fiji (Fiji present); Samoa (Samoa present), Peninsular Thailand present, Solomon Islands present
Peninsular Thailand; Hainan, Hong Kong; throughout Malesia; North Queensland, Solomon Islands, New Hebrides, Fiji, Samoa.
Notes
As here interpreted, this is a very variable species and varieties are not always sharply distinct; no formal names for them are here given. The following key attempts to distinguish the various forms.
KEY TO THE LOCAL FORMSLower pinnae lobed at least ⅔ towards costa and at least 1.5 cm wide.2Lower pinnae lobed not or little more than ½ way to costa, rarely more than 1.5 cm wide.5Glands none or rare on upper surface of pinnae.3Glands ± abundant on upper surface of pinnae.4Fertile pinnae of large plants 2 cm wide (sterile ones sometimes wider); costules 4 mm apart, second acroscopic vein usually touching side of sinus-membranetypical formFertile pinnae not over 1.5 cm wide; costules 3 mm apart; second acroscopic vein always to margin (Dryopteris suprastrigosa Rosenst.)New Guinea formAppressed hairs to 0.5 mm long between veins on upper surfaceBorneo formShort suberect hairs between veins on upper surfaceMoluccas formGlands and appressed hairs (sometimes dense) on upper surfaceBorneo (limestone) formGlands lacking on upper surface; appressed hairs variable, never dense.6Pinnae lobed distinctly more than ½; second acroscopic vein to margin.7Pinnae lobed ½ or less deeply; second acroscopic vein usually ending beside sinus-membrane. lowlands of W. Malesia formLower pinnae lobed not or little more than ½ way to costa, rarely more than 1.5 cm wide. Glands lacking on upper surface; appressed hairs variable, never dense. Pinnae lobed distinctly more than ½; second acroscopic vein to margin. Pinnae to 10 x 1.3 cm; costules at 60°; pinnae to 15 pairs; sori medial
Pinnae to 16 x 1.6 cm; costules almost at right angles to costa; pinnae more than 20 pairs; sori supramedialMindanao formPinnae to 10 x 1.3 cm; costules at 60°; pinnae to 15 pairs; sori medial (Nephrodium pubescens Brack., Dryopteris bordenii Christ)Luzon form
Backer & Posthumus cite Aspidium dimorphum Kunze as a synonym. This was based on a specimen of Junghuhn's from Mt Pangerango in W. Java; I have not found it. Mettenius (l.c. 1864) described it briefly as a synonym of A. heterocarpon var. B Bl. He stated that its aerophores were enlarged, for which reason I doubt whether it belongs here.
KEY TO THE LOCAL FORMSLower pinnae lobed at least ⅔ towards costa and at least 1.5 cm wide.2Lower pinnae lobed not or little more than ½ way to costa, rarely more than 1.5 cm wide.5Glands none or rare on upper surface of pinnae.3Glands ± abundant on upper surface of pinnae.4Fertile pinnae of large plants 2 cm wide (sterile ones sometimes wider); costules 4 mm apart, second acroscopic vein usually touching side of sinus-membranetypical formFertile pinnae not over 1.5 cm wide; costules 3 mm apart; second acroscopic vein always to margin (Dryopteris suprastrigosa Rosenst.)New Guinea formAppressed hairs to 0.5 mm long between veins on upper surfaceBorneo formShort suberect hairs between veins on upper surfaceMoluccas formGlands and appressed hairs (sometimes dense) on upper surfaceBorneo (limestone) formGlands lacking on upper surface; appressed hairs variable, never dense.6Pinnae lobed distinctly more than ½; second acroscopic vein to margin.7Pinnae lobed ½ or less deeply; second acroscopic vein usually ending beside sinus-membrane. lowlands of W. Malesia formLower pinnae lobed not or little more than ½ way to costa, rarely more than 1.5 cm wide. Glands lacking on upper surface; appressed hairs variable, never dense. Pinnae lobed distinctly more than ½; second acroscopic vein to margin. Pinnae to 10 x 1.3 cm; costules at 60°; pinnae to 15 pairs; sori medial
Pinnae to 16 x 1.6 cm; costules almost at right angles to costa; pinnae more than 20 pairs; sori supramedialMindanao formPinnae to 10 x 1.3 cm; costules at 60°; pinnae to 15 pairs; sori medial (Nephrodium pubescens Brack., Dryopteris bordenii Christ)Luzon form
Backer & Posthumus cite Aspidium dimorphum Kunze as a synonym. This was based on a specimen of Junghuhn's from Mt Pangerango in W. Java; I have not found it. Mettenius (l.c. 1864) described it briefly as a synonym of A. heterocarpon var. B Bl. He stated that its aerophores were enlarged, for which reason I doubt whether it belongs here.
Citation
v.A.v.R. 1908: Handb.: 822
Copel. 1960: Fern Fl. Philip.: 345
Tard. 1941 – In: Fl. Gen. I.-C.: 385
Mett. 1864 – In: Ann. Mus. Bot. Lugd.-Bat.: 233
v.A.v.R. 1908: Handb.: 228
C. Chr. 1929 – In: Gard. Bull. Str. Settl.: 380
Copel. 1960: Fern Fl. Philip.: 345
Backer & Posth. 1939: Varenfl. Java: 54
Holttum 1955: p. 269. – In: Rev. Fl. Malaya: f. 155
Copel. 1951 – In: Philip. J. Sci.: 446
Racib. 1898 – In: Fl. Btzg: 187