Here's a very interesting paper as pdf file: Kato, M., D. Darnaedi, and K. Iwatsuki. 1991. Fern Rheophytes of Borneo.
http://docs.google.com/viewer?a=v&q...xQodQG&sig=AHIEtbQa7V_88UMFXyQMFGmrZfgMgFA4Ow
On page 50, under No. 37:
Microsorum paucijugum. The description ("... Lamina deeply lobed to wings up to 5 mm broad; lateral lobes 3-4 pairs, conform to terminal lobe, ...") may be in line with the W. M. A. Brooke specimen from Nanga Mujong and with "Trident".
They write about
M. paucijugum: "This species may be considered a hydrophytic rheophyte. ... This species is closely related to the following,
M. pteropus, which is also a rheophyte. From morphology, distribution, and ecology, it is suggested that this species was derived from
M. pteropus."
According to tropicos.org it was described as
Polypodium paucijugum by Alderwerelt 1908 and was moved to
Microsorum by Iwatsuki & Kato 1981.
However,
M. paucijugum is listed as a synonym of
Microsorum pteropus by H.P. Nooteboom (1997, The microsoroid ferns).
The type specimen of
M. paucijugum (Teuscher s.n.) is in the herbarium of Bogor (Indonesia, Java). It would be interesting comparing it with the Brooke specimen and our cultivated "Trident" Java Fern.
