Nephrolepis falciformis
Content
Description
Habit, rhizome morphology.
Hairs on lamina absent, on costa sometimes present, few (usually forming a small group of scattered hairs near the base).
Distribution
Asia-Tropical: Borneo present; Malaya (Peninsular Malaysia present); Maluku (Maluku present); New Guinea present; Sri Lanka (Sri Lanka present); Sulawesi (Sulawesi present); Sumatera (Sumatera present)
Sri Lanka, Indochina; in Malesia: Sumatra, Peninsular Malaysia, Borneo, Celebes, Moluccas, New Guinea.
Notes
1. A fairly distinct species, most easily recognizable by the strongly falcate median pinnae and the strikingly light colour (fresh plants are bright green, dry specimens often, but not always, a pale yellowish brown). The degree to which the pinnae are falcate strongly varies within a single frond, with the median fertile pinnae often very pronouncedly falcate, with the apex frequently curved back somewhat towards the midrib, but the more basal and apical pinnae usually only slightly or not at all falcate. The sori are mostly nearly marginal, some hairs are usually present on the upper surface of the costae especially near the points of attachment, often forming a rather characteristic sparse tuft. The scales on rhachis are small and sparse, but rather conspicuous due to the dark colour.
2. A distinct form occurs on New Guinea, which differs from the typical form in a number of aspects: fronds long, slender, often stated to be pendent, often many in a tuft, strongly narrowed at base to strongly reduced (semicircular) basal pinnae, middle pinna relatively small and not strongly falcate; rhachis and fronds nearly glabrous, scales where present small. Typical plants of this form are at first sight similar to N. cordifolia, and have been distinguished as N. thomsonii and N. cordifolia var. calcarea. However, as all the characters that distinguish this form from typical N. falciformis show a very gradual transition between the two extreme states, we prefer to deal with it informally under this species.
2. A distinct form occurs on New Guinea, which differs from the typical form in a number of aspects: fronds long, slender, often stated to be pendent, often many in a tuft, strongly narrowed at base to strongly reduced (semicircular) basal pinnae, middle pinna relatively small and not strongly falcate; rhachis and fronds nearly glabrous, scales where present small. Typical plants of this form are at first sight similar to N. cordifolia, and have been distinguished as N. thomsonii and N. cordifolia var. calcarea. However, as all the characters that distinguish this form from typical N. falciformis show a very gradual transition between the two extreme states, we prefer to deal with it informally under this species.