Selliguea enervis

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Selliguea enervis

Distribution

Asia-Tropical:
Indochina. Throughout Malesia.

Notes

2. Specimens belonging to the following two species have frequently been misidentified as S. enervis:

Selliguea ceratophylla can be distinguished by the short rhizome and the pseudopeltate, small scales.

Selliguea pampolycarpa can be distinguished by the more closely set, long, spathulate fronds with two distinct ridges running along the upper surface of the costa.
1. Selliguea enervis is a very variable species, presenting a different aspect and pattern of variability in different areas:
  • Java, Sumatra, Peninsular Malaysia, Lesser Sunda Islands
    Usually large plants. Rhizome thick, scales dentate. Fronds virtually monomorphic, usually wide, ovate. Hydathodes mostly present, without persistent calcareous scales, sometimes very obscure or absent, margin not or only sporadically notched. Sori in 2 or 3 rows between veins, usually in many rows between costa and margin.
  • Philippines
    Plants more slender generally. Rhizome 1.5-2.5 mm thick, rhizome scales 3-4.5 by 0.5-0.7 mm, remotely and weakly dentate to short-dentate. Fronds weakly dimorphic. Fertile fronds: stipe 2.5-10 cm long; lamina 7-12 by 1.1-2.3 cm, index 0.9-11. Sterile fronds: stipe 0.5-5.5(-21) cm long; lamina 3-8(-18.5) by 1.6-2.8(-4.8) cm, index 1.5-4.4. Hydathodes absent. Margin notches regularly present.
  • Borneo
    Rhizome more widely creeping, 2.5-3 mm thick, internodes to 1.1-5 cm long. Rhizome scales 5.5-6 by 1.2-1.3 mm, short-dentate. Fertile fronds: stipe 3-24 cm long, lamina 7-23 by 1.8-5.8 cm, index 2.7-5.6, widest at 0.3-0.6 from base. Sterile fronds: stipe 2-13 cm long, lamina 7.5-13 by 2.6-4.6 cm, index 2.5-3.7. Hydathodes absent. Margin without notches or notches sporadically present, rarely notches regularly prsent.
    Polypodium kamboranganum was described on the basis of a specimen with fronds strongly dimorphic, the fertile ones with a single row of sori between costa and margin, hydathodes and marginal notches regularly present.
  • Sulawesi
    Several more or less distinct forms occur in Sulawesi, often represented by few specimens or by a single aberrant specimen. There is relatively much variation in the rhizome scales.
    Some of the more constant forms are:
    1. Rhizome 1.5-2 mm, long-creeping, internodes to 1.5-3.5 cm long. scales peltate, 3.5-5.5 by 0.4-1 mm, straw-coloured to brown (often mottled), remotely and weakly dentate to short-dentate. Hydathodes absent or sometimes present. Margin notches sporadically to regularly present.
    2. Rhizome 1.5-2 mm thick, short-creeping, internodes to 0.7-1 cm long. Rhizome scales pseudopeltate or peltate, 5-7 by 1-1.5 mm, acute to contracted to a narrow acumen, whitish to straw-coloured (sometimes brown), evenly coloured, often with a dull, thickened pseudocosta, remotely and weakly to short-dentate; acumen almost entire. Hydathodes absent. Margin notches regularly present.
    3. Rhizome 2.5-4 mm thick, short-creeping, internodes to 0.5-0.8 cm long. Rhizome scales pseudopeltate to peltate, spreading to squarrose, 4.5-7 by 0.5-0.8 mm, acute or contracted to a narrow acumen, straw-coloured to brown, remotely and weakly dentate to short-dentate. Hydathodes absent. Margin notches sporadically to regularly present.
  • New Guinea
    In New Guinea and the neighbouring islands there is an almost continuous range from large plants with a wide lamina to narrow, gramineous forms. In virtually all intermediates the presence of hydathodes and marginal notches is variable. As a consequence, forms that in other areas are distinguishable form a continuum here which cannot be divided. Transitional specimens with fronds of two different forms on a single rhizome sometimes occur.
    The following names have been applied to forms in this area.
    Polypodium reniferum (and, erroneously, P. taeniophyllum) to forms with long, gramineous fronds of less than 2 mm wide.
    Polypodium induratum to forms with long, narrow (sometimes very narrow) fronds with a single row of sori between costa and margin, usually without hydathodes. More distinctly dimorphic forms have often been identified as Crypsinus senescens, but the type of that is barely dimorphic. The name C. spathulatus better applies to these dimorphic forms.
    Crypsinus subundulatus, C. undulato-sinuatus and C. lamprophyllus to somewhat wider forms, with 1 or 2 rows of sori between the costa and the margin, and an often strongly but irregularly sinuate lamina margin. The differences between these forms and those called C. senescens are gradual.
    Polypodium petiolatum to specimens with a wider lamina, not or slightly dimorphic fronds, with 4 or 5 rows of sori between costa and margin. Hydathodes are frequent. This more or less forms a transition to S. hellwigii, which, however, differs in the constantly strongly dimorphic fronds.
    Polypodium rhomboideum Brause (non Blume) to small, barely dimorphic specimens. They are superficially similar to S. oodes from the Philippines, and sometimes difficult to distinguish from true S. oodes.
    A few specimens have been found with densely hairy fronds, but in no other way distinct from regular Selliguea enervis. Within Selliguea, hairiness is an exceptional character, occurring regularly only in a few species from continental Asia.

Citation

Alderw. - in Nova Guinea. 1924: 38
Baker, Syn. Fil. 1868: 359
Alderw., Malayan Ferns. 1908: 651
Sw., Syn. Fil. 1806: 28
J. Sm., Ferns Brit. & For. 1866: 95
Copel., Fern Fl. Philipp. 1960: 506
Holttum - in Revis. Fl. Malaya. 1954: 199
C. Chr. - in Dansk Bot. Ark. 1937: pl. 1, f. 4
Blume, Fl. Javae Filic. 1829: 142
Kato & Price - in Acta Phytotax. Geobot. 1990: 71
Alderw., Malayan Ferns. 1917: 525
Hovenkamp - in Blumea. 1998: 74
Backer & Posth., Varenfl. Java. 1939: 200
Alderw., Mal. Ferns. 1917: 387
Alderw., Malayan Ferns. 1908: 650
Alderw., Malayan Ferns. 1917: 379
Gepp in Gibbs, Arfak Flora. 1917: 75
Alderw., Malayan Ferns. 1908: 637