13. Polypodiastrum Ching, Acta Phytotax. Sin. 16(4): 27. 1978.
拟水龙骨属 ni shui long gu shu
Authors: Shugang Lu & Peter H. Hovenkamp
Plants medium-sized, epiphytic. Rhizome long creeping, densely scaly; scales brown to dark brown, lanceolate, clathrate. Fronds remote. Stipe articulate to rhizome at base. Lamina pinnate. Pinnae ca. 10 pairs, sessile, lanceolate to narrowly lanceolate, upper pinnae usually decurrent at base. Veins anastomosing to form 1-3 rows of areoles on each side of costa, each costal areole containing an included free veinlet. Lamina herbaceous, glabrous or minutely scaly on abaxial side. Sori orbicular, terminal on included veinlets of costal areoles, in 1 row on each side of costa; sporangia long stalked, annulus with 12-20 hardened cells. Paraphyses scalelike, clathrate, fugacious; spores ellipsoid, surface coarsely verrucate. x = 37.
About eight species: tropical and subtropical Asia and Oceania; three species in China.
Christenhusz et al. (Phytotaxa 19: 38. 2011) and Lindsay and Middleton (http://rbg-web2.rbge.org.uk/thaiferns/factsheets/index.php#P; accessed 2 Apr 2012) include Polypodiastrum within Goniophlebium.