144 MISS L. S. GIBBS ON THE FLORA AND PLANT FORMATIONS 
*ELATOSTEMA PENIBUKANENSIS, Gibbs, sp. nov. 
Herba erecta, tota glaberrima. Caulis tenuis, striatus, glaber. Folia 
alterna, petiolata, oblique lanceolata, basi obliqua in latere exteriore sub- 
aurieulata, in latere interiore acuta, apice tenuiter acuminata, crenata, 
membranacea, supra viridia, subtus pallidiora, cystolithis sub parenchymate 
absconditis difficillime aspectabilibus, supra prominenter, triplinervia, nervis 
lateralibus utrinque 2-3 tenuibus, nervis tertiariissubtus patulis, reticulatione- 
rufescente. 
Hat. Kinabalu, Penibukan spur, 5000', where it dips to the Kinitaki 
river. d. Feb. 4064. Above Lobang, 6000', in high forest undergrowth. 
d. 4120. 
This very delicate plant shows a ereeping rhizome, which sends up aerial 
shoots, about 7 em. apart, with yellow stems, the same colour as the rhizome. 
The shoots are more or less radial in habit, the stems being clothed with 
leaves for more than half their length. The stipules are colourless, very 
thin and membranous, 1:1-3 em. long and 2 mm. broad. The largest leaves 
are 45 mm. in length and 1:5 em. broad, with petioles 2-5 mm. long ; 
scattered cystoliths oceur on the upper surface of the leaves, but are only 
visible under a compound microscope. The attenuated peduncles of the g 
cymes vary from 1°5 em. to 3:5 em. in length, bearing cymes +8 mm. broad 
and 4 mm. high; the receptacle is flat and enclosed in six bracts, two 
larger and four smaller and narrower; the perianth of the ¢ flowers is 
5-partite, 2 mm. in length. 
This species is in radial habit and general appearance very near Æ. luzon- 
ense, C. B. Rob., well distributed in the island of Luzon, but differs in the 
total glabrousness of the whole plant, in the darker petiolate leaves with 
rounded erenate margins, in the fewer veins and conspicuous finer reticu- 
lations of the tertiary veins, also in the abseuce of cystoliths visible to the 
naked eye. 
Robinson, in treating of the Philippine Elatostemas (Phil. J. of Sci., Bot. 
v. (1910) 499, describes the flowers of Zlatostema as pedicellate * with a 
eup-shaped perianth, with very short round lobes, sometimes ciliate, but this 
last.is a most inconstant character.” He goes on to say, “apparently these 
are treated by Stapf (17. 231) as staminodes, but this interpretation would 
involve the presence of staminodes at the base of an ovary raised upon 
a common peduncle, which is quite distinct from anything else in the 
family." 
In an unpublished figure of ZQ. Lowii, on the type-specimen sheet in the 
Kew Herbarium, Dr. Stapf has shown a. gland-ciliate perianth with pointed 
lobes, and the infolded staminodes with rounded lobes above it. It is there- 
fore diffieult to see what other interpretation could be placed on the latter 
structures, when they are found to occur without the perianth, as is the 
case in Æ. bulbothriz, Stapf. 
