An epiphytic or rarely lithophytic fern; rhizome shortly creeping, stout, scaly; scales narrow, c. 1–2 cm long, slender at apex, latticed, dark brown, glossy; fronds in a crown. Stipe usually 15–40 cm long, grooved above, black, with some scales at base. Fronds usually pendulous to arching, c. 25–60 cm long, pinnate, with c. 15–37 pinnae which are gradually reduced towards apex; pinnae narrowly ovate, c. 5–13 cm long, unequal-sided, acuminate, coarsely serrate or double-serrate, cuneate and strongly oblique at base, ±glabrous, shortly stalked; lateral veins numerous, forked, free. Sori narrow, linear, along lateral veins; indusium linear.
Sickle Spleenwort, Mare's Tail Fern.
Christmas Is., a frequent and attractive epiphyte in the rainforest on the plateau and upper terrace. It usually forms the largest specimens when it grows on the water-retentive root ball of Asplenium nidus. It has once been collected from limestone rock crevices, growing with the endemic A. listeri. A widely distributed, Old World species, occurring from Madagascar and the Mascarenes through India, southern China, Indo-China, the Philippines and Malesia to Australia (W.A., S.A., Qld, N.S.W., Vic.), Polynesia and New Zealand.
Ch.Is.: plateau, H.N.Ridley 172 (K); limestone ridge 0.8 km S of Camp 4, D.A.Powell 110 (K); Headridge Hill, B.Molesworth Allen P8 (K); track to Grants Well, SW of Hanitch Hill, D.J. & B.P.Du Puy CI9 (CBG, K); Gannet Hill, on limestone rocks of lookout point over Margaret Knoll, D.J. & B.P.Du Puy CI88B (CBG, K).
This is an extremely variable speices or species complex, with regard to the size and division of the fronds. W.A.Sledge (Bull. Brit. Mus. (Nat. Hist.), Bot. 3: 235–277, 1965) gave a detailed account of a range of variants with entire, pinnatifid or pinnate pinnae found in Sri Lanka. Similarly D.L.Jones & S.C.Clemesha (Austral. Ferns & Fern Allies 2nd edn, 90, 1981) recorded this type of variation in Australia. Changes in frond shape may be linked with habitat and environmental factors, and may also involve alterations in ploidy levels. The specimen distinguished here as A. listeri is no doubt closely related to this complex, but it appears to be unique to Christmas Is., and differs so greatly from A. polyodon as represented on the island, that it has been maintained here as a distinct taxon.
listeriC.Chr. Ind. Fil. 118(1906)
A. centrifugale Baker, J. Linn. Soc., Bot. 25: 360 (1890), non Baker (1874), nom. illeg.T: [Christmas Is., Sept.–Oct. 1887, J.J.Lister s.n.; holo: missing from BM & K]. Gannet Hill, in exposed crevices on limestone rocks of lookout point over Margaret Knoll, Christmas Is., 29 Apr. 1987, D.J. & B.P.Du Puy CI88A; neo: K; isoneo: CBG, fide D.J.Du Puy, Fl. Australia 50: 573 (1993). Named after Joseph Jackson Lister, an Englishman educated at Cambridge, who embarked at Colombo [Sri Lanka] as volunteer naturalist on H.M. Survey Vessel Egeria, and landed on Christmas Is. on 30 September 1887, where he collected specimens for about a week in the vicinity of Flying Fish Cove.
A small, lithophytic fern; rhizome shortly creeping, scaly; scales narrowly ovate, c. 3–6 mm long, long-acuminate, latticed, dark brown, glossy; fronds in a crown. Stipe slender, c. 2.5–3.5 cm long, slender, black, with some scales at base. Fronds short, erect, c. 3.5–9 cm long, with c. 8–18 pinnae which are gradually reduced towards apex; pinnae ovate, c. 8–18 mm long, with several lobes divided to near midvein, unequal-sided, incised and toothed, cuneate at base, ±glabrous, coriaceous, with stalk 0.3 mm long; lateral veins forked, free. Sori linear along lateral veins; indusium linear.
Christmas Island Spleenwort.
Christmas Is. Endemic. Occurs on exposed limestone rocks and cliffs at a single locality.
Originally collected by J.J.Lister in 1887, probably near Flying Fish Cove. It was not collected by C.W.Andrews, but H.N.Ridley, J. Straits Branch Roy. Asiat. Soc. 45: 246 (1906), reported having found a single small specimen at Toms Ladder, again in Flying Fish Cove. These historical collections have been lost, and there had been some mystery concerning the identity of this species. J.G.Baker, J. Linn. Soc., Bot. 25: 360 (1890), described the plant as having pinnate fronds c. 10–13 cm long, c. 2.5–4 cm wide, with stipes c. 5–7.5 cm long. He described the pinnae as being deeply lobed, with the sori confined to the lobes, leaving the central regions of the pinnae sterile and naked.
A specimen recently collected from crevices in exposed limestone rocks at the viewpoint in Gannet Hill (D.J. & B.P.Du Puy CI88A), closely resembles the above description of A. listeri, although with slightly smaller fronds. As this is the only specimen available of this species, it has been neotypified here, and the description has been drawn up from this single collection.
A larger specimen (D.J & B.P.Du Puy CI88B), was collected along with the above specimen of A. listeri, growing in the same rock crevice. It is much larger than A. listeri (frond laminas 16–27 cm long), and the pinnae are not lobed, but toothed as in A. polyodon, from which it differs only in its slightly smaller size, and somewhat more coriaceous and suberect fronds. This specimen has therefore been included in A. polyodon. The large variation in the morphology of A. polyodon has already been discussed, but does not appear to include the distinct variant distinguished here as A. listeri.
D.J.DuPuy(Ch.Is.)Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, EnglandA.E.Orchard(M.Is.)Australian Biological Resources Study, GPO Box 767, Canberra, Australian Capital Territory, 2601
Terrestrial ferns; rhizome erect or creeping, the apex covered in non-latticed scales; stipes not articulate on rhizome, with scales or multicellular hairs. Fronds usually 1- to 4-pinnate, rarely simple; rachis and costae scaly or with multicellular hairs; veins free or netted; pinnules asymmetrical. Sori round, on veins or ends of veins; indusia peltate or reniform, rarely absent.
A family containing many genera whose classification is still unsettled. It is distributed throughout the world; 2 genera on Christmas Is.; 1 genus on Macquarie Is.
KEY TO GENERA
1 Pinnae oblique at base (M.Is.)
1: Pinnae equal-sided at base (Ch.Is.)
2 Pinnae mostly simple, entire, the basal pair of pinnae of basiscopically lobed
2: Pinnae mostly deeply lobed to pinnately divided, with toothed or lobulate lobes
3 Lowest pair of pinnae more finely divided than upper pinnae; sinus between pinna lobes without a tooth at base
3: Lowest pair of pinnae identical to upper pinnae; sinus between pinna lobes with a small, prominent tooth at base
PolystichumRoth Tent. Fl. German. 3: 31, 69(1799) from the Greek poly- (many) and stichos (a row), in reference to the arrangement of the sori
Type: P. longchitis (L.) Roth
Terrestrial; rhizome erect, densely covered in scales. Fronds large, 2- or 3-pinnate; rachis usually densely scaly; pinnules asymmetric. Sori circular, in 1 row either side of midrib, remote from margins; indusion circular, peltate or absent.
A cosmopolitan genus of about 160–180 species; 4 species in south-eastern Australia; 1 species on Macquarie Is. Mainly found in temperate areas of both hemispheres and mountainous areas in the tropics.
T.F.Cheeseman, Vasc. Fl. Macquarie Is. 39 (1919), as Aspidium; B.W.Taylor, Fl. Veg. Soils Macquarie Is. 154–155 (1955); H.H.Allan, Polystichum, Fl. New Zealand 1: 87–89 (1961); G.R.Copson, Annotated Atlas of the Vascular Flora of Macquarie Island, ANARE Res. Notes 18: 27 (1984).
Polystichum venustum Hombr., Voy. Pôle Sud t. 5m–n. (1843); Aspidium venustum (Hombr.) Hook.f., Fl. Antarct. 1: 106 (1844).T: no specimen cited; n.v.
Illustrations: B.W.Taylor, Fl. Veg. Soils Macquarie Is. pl. 24 (1955); P.J.Brownsey & J.C.Smith-Dodsworth, New Zealand Ferns & Allied Pl. pl. 30D, figs 165, 167 (1989).
Terrestrial; rhizome short, erect, scaly; frond 22–60 cm long. Stipe densely scaly; scales linear to triangular or ovate, 2–4 cm long, long-attenuate, brown, papery, those nearer base with dark brown centre, interspersed with long flattened bristles. Fronds with primary rachis similarly clothed but scales shorter; upper rachis scales dark brown with light margin; lower rachis scales often uniformly light; indumentum sometimes sparse; secondary rachis usually with bristles only or almost glabrous. Lamina bipinnate, oblong to narrowly lanceolate, tapering, truncate at base; primary pinnae usually 15–40 pairs; secondary pinnae mostly 9–13 pairs, ovate, oblique, deeply dentate, acute, to 10 mm long, 6 mm wide. Sori 3–7 per pinnule, usually 5, round, c. halfway between margin and midrib; indusium peltate, light brown.
Macquarie Is. Localised in valleys on the eastern side of the island, rare on the west. Extends from Tasmania and New Zealand (North, South, Stewart, Chatham, Auckland, Campbell, Antipodes and Snares Islands) to Macquarie Is.
M.Is.: on southern slopes of Nuggets Ck, R.Filson 6374 (HO); Green Gorge, 18 Jan. 1949, N.R.Laird (HO); Nuggets Ck valley, 12 Feb. 1949, N.R.Laird (AD, AK, BISH, CANB, CBG, CHR, H, HO, MEL, NSW, WELT); Finch Ck, Sandy Bay, R.D.Seppelt 12675 (AD, AK, HO, MEL).
TectariaCav. Anales Hist. Nat. 1: 115(1799) from the Latin tectus (covered, concealed), in reference to the indusia which cover the sori
Type: T. trifoliata (L.) Cav.
Medium to large, terrestrial ferns; rhizome creeping to erect, sometimes thick, covered by the persistent stipe bases; roots numerous, wiry; fronds in a crown, or closely to widely spaced. Scales large, entire, conspicuous on rhizome apex and scattered on stipe base. Stipe not deeply grooved, often becoming brown; vascular strands several, small. Fronds pinnate to tripinnatisect, rarely simple, the basal pair of pinnae often basiscopically lobed or more finely divided than the others, sometimes dimorphic; veins usually anastomosing, forming areolae (not in T. dissecta). Sori usually circular, terminal on free veinlets; indusium usually reniform or peltate; paraphyses absent.
A pantropical and subtropical genus of c. 150 species; 3 species on Christmas Is.
The species are very variable in frond shape, venation, soral position, indusial type and indumentum, and have previously been variously split into several taxa. There is an evolutionary trend in this genus towards a reduction in the degree of dissection of the fronds, perhaps as an adaptation to damp, windless environments. They usually occur in damp, shady forests, especially on streambanks, rocks or gullies. They show some preference for calcareous rocks and can occur on the mortar of old walls.
The Malesian species have been revised by R.E. Holttum, who kindly allowed the use of his unpublished manuscript (Pteridophyta, Tectaria Group, Fl. Males. ser. II, 2, 1: 1–132, 1991).
R.E.Holttum, Fl. Malaya (Ferns) 2nd end, 2: 501–519 (1968); R.E.Holttum, The fern genus Tectaria in Malaya, Gard. Bull. Singapore 34: 132–147 (1981); R.E.Holttum, Studies in the fern genera allied to Tectaria Cav. VII. *Species of Tectaria sect. Sagenia (Presl) Holttum in Asia excluding Malesia, Kew Bull. 43: 475–489 (1988); D.L.Jones & S.C.Clemesha, Austral. Ferns & Fern Allies 2nd edn, 206–208 (1981); R.M.Tryon & A.F.Tryon, Ferns & Allied Pl. 470–481 (1982).
1 Fronds pinnate, sometimes with a basiscopic lobe on the basal pinnae
3. T. siifolia
1: Fronds much more finely divided, 2- or 3-pinnatisect
2 Veins anastomosing, forming areolae along midveins of pinnae, pinnules and lobes; fronds tripinnatisect, the pinnae mostly bipinnatisect; basal pair of pinnae with stalks c. 1.5–2.5 cm long; sori mainly in lobules of pinna lobes; indusia glabrous
1. T. devexa
2: Veins all free; fronds bipinnatisect, the pinnae pinnatisect except for the basal pair which have 1–3 pairs of stalked pinnules; basal pair of pinnae with stalks up to 1.5 cm long; sori in single rows on either side of midvein of pinna lobes; indusia hairy
2. T. dissecta
devexa(Kunze ex Mett.) Copel. Philipp. J. Sci. (Bot.) 2: 415(1907)
Aspidium giganteum var. minor Hook., Spec. Fil. 4: 50 (1862).T: Ceylon, G.Thwaites CP1358; holo: K, fide R.E.Holttum, loc. cit. (1988). Epithets from the Latin devexus (descending, sloping), in reference to the frond shape; and from the Latin minor (lesser, smaller).
Illustration: D.L.Jones & S.C.Clemesha, Austral. Ferns & Fern Allies 2nd edn, fig. 288 (1981), as T. devexa.
Terrestrial fern; usually solitary; rhizome suberect to procumbent, thick; scales narrowly ovate to linear, c. 6–9 mm long, dark brown; fronds in a crown. Stipe C. 10–35 cm long, becoming brown. Fronds arching, c. 20–40 cm long, tripinnatisect, thinly herbaceous; pinnae bipinnatisect, the basal pinnae largest and most deeply divided, with stalks 1.5–2.5 cm long; lobes narrowly triangular, mostly lobulate, acute, to 4–7 cm long; veins densely hairy; lamina sparsely hairy above and in sinuses; veins anastomosing, forming elongated areolae along larger veins. Sori small, circular, mainly in lobules of pinna lobes; indusia reniform, glabrous.
Christmas Is. Grows in shaded positions in the primary rainforest on the plateau, usually in areas of deep soil. It may be the only forest floor species in this type of habitat. A tropical and subtropical species distributed from Taiwan, southern China and Sri Lanka through Indo-China, the Philippines and Malesia to the New Hebrides and Australia (Qld). Var. minor is known only from Sri Lanka and Christmas Is.
Ch.Is.: no precise locality, Sept.–Oct. 1988, J.J.Lister (K); no precise locality, C.W.Andrews 12, 131 (K); Flying Fish Cove, H.N.Ridley 186 (K); S side of island, Line 256, D.J. & B.P.Du Puy CI17 (CBG, K).
Var. minor differs from the typical variant in having frond laminas which are almost glabrous beneath, although the veins are hairy. This species closely resembles T. dissecta, with which it shares similar habitat preferences. Tectaria dissecta has less finely divided fronds with no anastomosing veins.
dissecta(G.Forst.) Lellinger Amer. Fern J. 58: 156(1968)
Polypodium dissectum G.Forst., Prodr. 81 (1786); Nephrodium dissectum (G.Forst.) Desv., Mém. Soc. Linn. Paris 6(2): 259 (1827); Lastrea dissecta (G.Forst.) Carr, B.Seemann, Fl. Vit. 360 (1873).T: Pacific, G.Forster; iso: BM, K. Epithet from the Latin dissectus (cut into pieces), descriptive of the finely divided fronds.
[Lastrea blumei auct. non T.Moore (1858): H.N.Ridley, J. Straits Branch Roy. Asiat. Soc. 45: 247 (1906)]
[Nephrodium intermedium auct. non (Blume) Hook. & Baker (1867): C.W.Andrews, Monogr. Christmas Is. 195 (1900)]
Terrestrial fern, usually solitary; rhizome suberect; scales narrowly ovate, c. 4–8 cm long, dark brown; fronds in a crown. Stipe c. 25–30 cm long, becoming brown. Fronds arching, 30–60 cm long, ±bipinnatisect excluding basal pair of pinnae, thinly herbaceous; pinnae mostly pinnatisect, the basal pair largest and most finely divided, ±bipinnatisect, with 1–3 pairs of pinnules, and stalks to 1.4 cm long; lobes narrowly oblong, mostly to 3 cm long, rounded, mostly shallowly toothed; lamina sparsely hairy above; veins all free, densely hairy. Sori small, circular, in single rows on either side of midvein of pinna lobes; indusia reniform, hairy.
Christmas Is. Not uncommon, in deep soil on the plateau and upper terraces, in deeply shaded positions under primary rainforest. Occurs from Taiwan, through the Philippines, Borneo and Sulawesi to Java, the lesser Sunda Islands, and Christmas Is., and east through New Guinea to the SW Pacific islands.
Ch.Is.: Phosphate Hill, H.N.Ridley 182 (K); Murray Hill track, H.N.Ridley 183 (K); sheltered valley close to Aldrich Hill, D.A.Powell 456 (K); Headridge Hill, B.Molesworth Allen P10 (K); S side of island, Line 256, D.J. & B.P.Du Puy CI20 (CBG, K).
siifolia(Willd.) Copel. Philipp. J. Sci. (Bot.) 2: 414(1907)
Polypodium siifolium Willd., Sp. Pl. 5: 196 (1810).T: Java, L.Ventenat s.n., Herb. C.L.Willdenow 19689; holo: probably B n.v., fide R.E.Holttum, Fl. Males. ser. II, 2, 1: 84 (1991). Epithet from the Latin folium (a leaf) and the genus Sium (Apiaceae), because of the similar appearance of the foliage of these two taxa.
[Nephrodium polymorphum auct. non (Wall. ex Hook.) Hook. & Baker (1868): C.W.Andrews, Monogr. Christmas Is. 195 (1900)]
[Aspidium polymorphum auct. non Wall. ex Hook. (1862): H.N.Ridley, J. Straits Branch Roy. Asiat. Soc. 45: 247 (1906)]
Terrestrial fern; rhizome shortly creeping; scales to 10 mm long, dark brown; fronds clustered near apex. Fronds pinnate, with 1–4 pairs of pinnae, the lowest pair sometimes lobed to bifid, glabrous, dimorphic, the sterile frond with broader pinnae than the fertile ones, and with a shorter stipe; pinnae entire or with sinuous margins. Fertile frond: stipe to 50 cm long; pinnae narrowly oblong, 9–22 cm long, to 5 cm wide, acuminate, obtuse at base; lateral veins oblique, with a network of anastomosing veins between, forming many areoles. Sori circular, in paired rows between lateral veins of pinnae, sometimes coalescing into short, linear sori; indusia small, reniform, glabrous.