Blechnum indicum

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Blechnum indicum

Distribution

Asia-Tropical: Jawa (Jawa absent), Fiji Islands absent, New Caledonia present, SE Asia present, coastal northern and eastern Australia as far south as latitude 31°01'S present
Malesia: Throughout (?except Java). Outside Malesia: Widely distributed in SE Asia and extending as far south as New Caledonia but not as far east as the Fiji Islands. It also occurs in coastal northern and eastern Australia as far south as latitude 31°01'S.

Cytology

n = c. 37 () for New Caledonian material.

Uses

The fresh croziers and young fronds are often seen being sold in bunches in markets in SE Asia. There are also reports of the rhizomes being used to make a coarse flour (e.g. I. van der Harst s.n., Frederik Hendrik Island off the south coast of Papua, refers to the plant as kadu and the flour as akar pakoe pakoe NSW 295951). The croziers in some countries are canned and regarded as a delicacy said to be somewhat like asparagus in texture and flavour.

Notes

1. Blechnum indicum is closely related to but distinct from B. serrulatum Rich., from South and Central America, Florida, and the Caribbean Islands, which was reported in error from Australia by Hooker & Baker (), Bentham (), and others.
2. Blechnum serrulatum is most readily distinguished by having pinnae (especially the sterile pinnae) which are broader and not tapering evenly from the base to the apex but are oblong and shortly acute at the apex. Isolated fronds do sometimes have pinnae tapering evenly but specimens with a range of fronds almost invariably have some with oblong pinnae with shortly acuminate apices. The abaxial costal scales of B. indicum are clathrate and are very small with reddish brown cross walls; those of B. serrulatum are paler, slightly larger and less distinctly clathrate. The veins of the pinnae in B. indicum are usually distinct on both surfaces while those of B. serrulatum tend to be more immersed and indistinct on the lower surface. The pinnae of B. serrulatum are more distinctly coloured with the upper surface shiny and often a dark bronze colour. The pinna margins tend to more regularly serrate to denticulate.
3. The holotype of B. indicum from Java is lost. A specimen with what appears to be an original herbarium sheet and label at Herbier Delessert, Geneva, was identified and annotated on 10.9.1951 by F. Ballard at Kew as Asplenium longissimum Blume. The brief Latin description, “Felix Lonchitidis facie, alis denticulatis dupliciter auriculatis” matches that part of the original publication in Burman’s Flora Indica 1768. It is not known either when or by whom this specimen of Asplenium longissimum was attached to this sheet.
4. We have examined a wide range of specimens from most parts of the Malesian region but have not seen material from Java. This is somewhat puzzling for such an abundant, widespread and widely utilised species. [Note of the editor: It is uncertain whether Pryon, the collector of the type, ever was in Java. The species does not figure in Backer & Posthumus, Varenflora of Java].

Citation

Burm.f. 2001 – In: Blumea. p 313
T.C.Chambers & P.A.Farrant 1998 – In: Fl. Australia. 372, 710
S.B.Andrews 1990: Ferns Queensland: 94. f. 7.4A
Holttum 1954: p. 446. – In: Revis. Fl. Malaya. f. 259a, 260c
Brownlie 1969: p. 237. – In: Fl. Nouv.-Calédonie. pl. xxx, f. 3, 4