三羽新月蕨 san yu xin yue jue

Meniscium triphyllum Swartz in Schrader, J. Bot. 1800(2): 16. 1801; Abacopteris triphylla (Swartz) Ching; Cyclosorus triphyllus (Swartz) Tardieu; Dryopteris triphylla (Swartz) C. Christensen; Nephrodium triphyllum (Swartz) Diels; Phegopteris triphylla (Swartz) Mettenius; Thelypteris triphylla (Swartz) K. Iwatsuki.

Plants 20-50 cm tall. Rhizomes long creeping, blackish brown, with dense white hooked short hairs and brown hairy lanceolate scales. Fronds monomorphic or dimorphic; stipes 10-40 cm, dark stramineous, bases with sparse scales and throughout with dense curved short hairs; laminae ovate-triangular, 12-20 × 7-11 cm, rounded at bases, ternate, long acuminate at apices; lateral pinnae 1 pair (rarely 2 pairs), oblique distally, opposite, oblong-lanceolate, 5-9 × 1.5-2.5 cm, bases rounded or rounded-cuneate, stalk 1-2 mm, margins entire, apices shortly acuminate; terminal pinna very large, lanceolate, 15-18 × 3-3.5 cm, bases rounded or rounded-cuneate, stalk 6-12 mm, margins entire or undulate, apices acuminate. Veins evident abaxially, veinlets obliquely spreading and parallel, veins in middle of pinnae usually 8 or 9 pairs oblique or spreading, veinlet pairs joining by their ends and forming triangular areoles, an excurrent veinlet arising from joining point connected with veinlets of others forming subsquare areoles. Laminae firmly papery, adaxially glabrous except for dense hooked hairs in costal grooves, abaxially with hooked hairs along costae and veinlets and also with scattered hooked hairs on intercostal areas. Fertile fronds slightly taller than sterile ones, stipes longer, pinnae narrower. Sori attached on veinlets, orbicular when young, becoming narrowly ovate and confluent, exindusiate; sporangia each with 2 hooked hairs.

Forests; 100-600 m. Fujian, Guangdong, Guangxi, Taiwan, SE Yunnan [India, Indonesia, Japan, S Korea, Sri Lanka, Malaysia, Myanmar; NE Australia].

The correct position of Abacopteris triphylla var. simplicifolia Ching (Bull. Fan Mem. Inst. Biol., Bot. 8: 243. 1938) is not known. Cyclosorus ×pseudoliukiuensis (Serizawa) Ralf Knapp (Ferns Fern Allies Taiwan, 445. 2011; Thelypteris ×pseudoliukiuensis Serizawa) is the putative hybrid between Pronephrium triphyllum (as C. triphyllus) and the following species, P. cuspidatum (as C. liukiuensis).