Davallia repens (Linnaeus f., 1781) Kuhn, 1869
Description
Rhizome without the scales 0.5-3 mm in diametre, white waxy under the scales (D. repens Rhizome). Scales brown or red-brown, with pale border from base to apex or not, narrowed evenly towards the apex, not or seldom curling backward, bearing multiseptate hairs at least when young or, with marginal setae at least in distal part, peltate, 2.5-7 mm long by 0.3-1.5 mm broad. Stipes adaxially grooved, 0.1-18 cm long, glabrous or with few scales. Lamina compound (pinnate with pinnatilobed to pinnatifid pinnae, or bipinnate to quadripinnate towards base and in the middle part) (D. repens Habitus2), simple (one pectinate or pinnatifid leaf) (D. repens 03, habitus), 3-foliate (the leaflets more or less divided) (D. repens 01, habitus), or pinnate towards base, ovate, deltoid and broadest towards base, glabrous, 0.6-24 cm long by 0.5-14 cm broad, strongly dimorphous or not or slightly dimorphous. Longest petiolules 0-4 mm long. Pinnae linear-triangular, narrowly ovate, linear, or ovate to deltoid. Longest pinnae 1-10 cm long by 0.6-7 cm broad. Pinnules (if present) of at least the larger pinnae anadromous, linear oblong or narrowly ovate. Longest pinnules 5-55 mm long by 5-20 mm broad. Ultimate leaflets (if present) lobed almost to the midrib or only shallowly lobed. Ultimate segments or lobes obtuse or acute without a tooth. In dimorphous plants lamina of fertile leaves pinnate with strongly dissected pinnae, bipinnate, or tripinnate towards base and in the middle part. Longest petiolules of fertile leaves 1-7 mm long. Pinnae deltoid, linear-triangular, or narrowly ovate, 1-8 cm long by 0.3-2.5 cm broad. Pinnules or pinnalobes deltoid, or linear-oblong, 2-35 mm long by 1.5-15 mm broad. Ultimate leaflets linear oblong. Ultimate segments of fertile leaves 1-15 mm long by 0.5-2 mm broad. Leaf axes glabrous. Veins in sterile ultimate lobes simple, forked, or pinnate, reaching the margin. False veins not present. Sori separate, borne several on a segment, or in much divided leaves frequently single on a segment, at the forking point of veins. Indusium attached at the broad base and hardly or not at the sides, semicircular or more or less triangular to rhomboid, wider than long, about as wide as long, 0.3-1 mm long by 0.3-1.3 mm broad, upper margin not elongated, truncate or slightly rounded, separated from or even with lamina margin (D. repens SEM1, D. repens SEM5, pictures of indusia). Lamina generally extending into a tooth at both sides or only at the outside of a sorus, or not extending into teeth beyond a sorus.
Distribution
Africa: Cameroun; Gabon.
Indian Ocean: Comores and Madagascar (many coll.); Seychelles (3 coll.), Mascareignes, Reunion and Mauritius (many coll.); Kerguelen (Bourbon Island 1 coll.).
Continental Asia: Sri Lanka and throughout India (many coll.); Sikkim (2 coll.); Southern Burma (1 coll.), China (Kiangsi 4 coll., Szechuan 3 coll., Kweichow 3 coll., Fukien 10 coll., Quangdong incl. Hongkong many coll., Kwangsi 5 coll., Yunnan 7 coll., Hainan 15 coll., Taiwan many coll.); Japan (Honshu, Shikoku, Kyushu, Yakushima, Okinawa, many coll.); Thailand (many coll.); Cambodia (5 coll.), Vietnam (many coll.).
Malesia: Throughout (many coll.).
Australia: Queensland (many coll.).
Pacific: Common in Admiralty Islands, Lashed Islands, Solomon Islands, Vanuatu, New Caledonia, Fiji, and Samoa.
Ecology
Very diverse. Low or high epiphytic, epilithic on various kinds of rocks, sometimes terrestrial. In very wet to dry sunny places. Altitude 0-3420 m.
Note
This is a very variable species. On the base of herbarium specimens it is not possible to subdivide it, which results in a very unsatisfying and extremely variable species. The species is probably subject to hybridizing and introduction of genes from several related species. From Sri Lanka an apogamous triploid was described by Manton and Sledge (Manton and Sledge, 1954). In areas where no related species are found, like in China, the islands in the Indian Ocean, and in Africa, only the pure form with pinnate to pinnatifid leaves occurs. In New Guinea the pure form is very rare. I have tried to subdivide the species in varieties. Although some forms are rather constant even over large areas, there are always many intermediate forms found between all the rather constant ones, making identification impossible. The pure form is generally found at lower altitudes, the other forms at higher ones. In W. Java, for instance, the pure form occurs from 450-1100 m, the other forms from 1400-2500 m. In Peninsular Malaya this is from 150-1600 and from 1400-2000 m. In Borneo, however, the pure form is found from 0-2500 m, the other forms from 100-3150 m. In the Philippines this is from 500-1350 m and from 400-2500 m, respectively.