海南金星蕨 hai nan jin xing jue

Thelypteris subimmersa Ching, Bull. Fan Mem. Inst. Biol., Bot. 6: 306. 1936.

Plants 2.6-3 m tall. Rhizomes strong, woody and ascending. Fronds approximate; stipes nearly to 1 m, thick, ca. 1 cm in diam., bases with thick lanceolate scales, distally with sparse short setae, dark stramineous; laminae large, oblong-lanceolate, 160-200 × 50-60 cm, bases nearly tapering or sometimes proximal pair of pinnae slightly shortened, pinnate-pinnatifid, acuminate and pinnatifid at apices; pinnae mostly subopposite, spreading, sessile; middle pinnae linear-lanceolate, 25-30 × 2-2.5 cm, bases symmetrical, truncate, pinnatifid and reaching both narrow wings of costae, apices caudate-acuminate; segments 60-70 pairs, flatly spreading, pectinately arranged, linear, 8-10 × 2.2-2.5 mm, entire, rounded or acute at apices. Veins evident, lateral veins simple, 12-14 pairs per segment, proximal pair arising from base of costules, all reaching margins above sinuses or basal acroscopic veinlet close to sinus. Laminae papery, when dry grass-green, pinnae abaxially ± with yellow spherical small glands along veins, elsewhere glabrous, adaxially along grooves with dense grayish white fine and long acicular hairs and along veins sparsely shortly hairy. Sori orbicular, medium-sized, dorsifixed at middle of lateral veins, 8-10 pairs per segment; indusia orbicular-reniform, somewhat leathery, glabrous, sulfur-colored glands along margins, persistent. Spores orbicular-reniform, perispores echinate.

● On wet sandy soils in forests on slopes. W Hainan.

Parathelypteris subimmersa is similar to Amphineuron immersum, which grows in Malaysia. The latter differs in having pinnae broader (3-3.3 cm), segments with dense grayish white fine and long acicular hairs abaxially. Owing to more complex characters on Amphineuron, except that the plant of this species is particularly large and strong, other characters do not differ, so it is listed here.