903 



€l)c Erea^ury af 230tanj), 



[PLEC 



ternately long and short, with dilated fila- 

 ments ; and an ovary with three projecting 

 1 keel-like wings : and the styles combined 

 into one thread-shaped column, longer than 

 | the stamens. The name is derived from 

 ! Greek words signifying'tlat-thread,' in allu- 

 i sion to the dilated filament. [M. T. M.J 



PLATTPODITJM. A genus of Legumi- 

 I nosce of the tribe Dalbergiew, with tbe 

 | flowers nearly of Pterocarpus and of Ti- 

 ! ptiana, while the pod is samara-like as in 

 the latter genus; but the wing, instead of 

 i being a dilatation of the style and conse- 

 quently placed above tbe seed-bearing part, 

 is an expansion of the stalk and below the 

 seed. It is like a Tipuana pod attached by 

 the wrong end. The genus consists of three 

 Brazilian trees, with pinnate leaves, and yel- 

 I low flowers growing in handsome loose 

 racemes in the axils of the upper leaves. 

 They probably supply some of the hard 

 woods used in Brazil. 



PLATrS. 

 broad. 



In Greek compounds = 



PLATYSEMA. A little-known Brazilian 

 bean, formerly proposed by Beutbam as a, 

 distinct genus of the tribe Phaseolece, but j chides standing like so manycoarsebristles. 



habiting the sandy plains of South-west 

 Australia. Tbey are elegant little evergreen 

 shrubs, with linear leaves arranged in 

 whorls somewhat resembling those of Ga- 

 lium. The pedicels bear one flower of a 

 purplish-lilac colour, and only opening 

 once on a bright day, but never when the 

 sky is overcast or night is approaching ; 

 whilst in its ally, Tetratheca, the flowers 

 open and close repeatedly on bright days, 

 closing on the approach of night or showers 

 of rain, as Dr. Steetz has well observed. 

 The calyx is five-cleft, the corolla flve-pe- 

 talous, tbe stamens ten in number, the 

 capsule two-celled and two-valved. P. ga- 

 lioicles (Tremandra verticillata) is an inmate 

 of our greenhouses. [B. S.] 



PLATYZOMA. The only species of tins 

 genus, P. microphyllum, is a curious dwarf 

 linear-fronded fern of the Australian con- 

 tinent, with minute sessile suborbicular 

 pinna?, having the margins so decidedly 

 revolute that the sori, which are non-in- 

 dusiate, consisting of from two to four 

 sessile spore-cases, are with great difficulty 

 discovered. These pinnae readily fall off, 

 leaving the crowded rigid stipites and ra- 



most probably a species of Centrosema. 



PLATYSTEMMA. A somewhat dubious 

 genus of Gesneracece of the tribe Ci/rtav- 

 drece, represented by a single specfes, P. 

 violoides, inhabiting Nepal, and having the 

 habit of a violet. It is a low herb, the 

 stem of which bears towards the apex 

 one or two cordate and crenate leaves. 

 The peduncle has from one to four flowers ; 

 the calyx is five-cleft ; the corolla has a 



The plant belongs to the Gleicheninece, and 

 indeed its fronds most nearly resemble 

 single branchlets of those small-pinnuled 

 species of Gleichenia which have saccate 

 or pouch-formed segments. [T. M.J 



PLECOLEPIS. An involucre of compo- 

 sites, in which the bracts are united into 

 a cup, 



PLECOSTIGMA. A genus of Liliacece 



from Siberia, founded upon Gagea pauci- 



short tube and is bilabiate, the upper lobe flora, which is separated from the others 



being two-cleft, the lower three-cleft; there 

 are four stamens; the style is filiform; the 

 stigma acute ; and the fruit a two-celled 

 oblong capsule. [B. S.] 



PLATYSTEMON. Annuals belonging to 

 the Papaveraceoe, among which they are 

 distinguished by having three sepals, six 

 petals, dilated filaments (whence the genus 



on account of the stigma being three-cleft, 

 each lobe longitudinally folded within, and 

 the seeds oblong-trigonous. The flowers 

 are yellow, one to three in a raceme, with 

 two bracts at the base. Bulb simple ; root- 

 leaves few, filiform, at length elongated , 

 stem-leaves scattered linear. [J. T. S.J 



PLECTOCOMIA. A genus of palms, of 



derives its name), and numerous distinct wnich two species'are confined to Malacca 



many-celled capsules. Two species have 



been described: P. californicus, a hairy 



spreading plant with lanceolate leaves ar- 

 ranged in threes, solitary stalked yellow 



flowers, and hairy capsules ; and P. leio- 

 ■. carpus, a native of Siberia, distinguished 

 1 by its yellowish-white flowers, and smooth 



capsules. [C. A. J.J 



PLATYSTIGMA. A Californian annual 

 belonging to the Papaveracece, distinguish- 

 ed by its three sepals, four to five petals, 

 thread-like filaments, three erect divergent 

 stigmas, and its one-celled three-valved 

 capsule opening from top to bottom. The 

 stems, which are very short, are densely 

 crowded with linear entire leaves, from 

 among which rise on slender hairy stalks 

 the solitary yellow flowers. The whole 

 plant grows to the height of about six 

 inches. [C.A.J.J 



PLATYTHECA. A genus of Tremandra- 

 ceaz, consisting of a couple of species in- 



Penang, Java, and Borneo, and three are 

 found in Assam, Khasia, and the Hima- 

 layas. They are allied to the rattans 

 (Calamus), and like them are inhabitants 

 of forests. Their climbing stems, though 

 stouter than the generality of Calami, re- 

 quire other trees for their support ; and in 

 order that they may take a firm hold among 

 the branches, their large pinnate leaves are 

 furnished with long whip-like tails, beset 

 on the under-side with excessively strong 

 compound spines shaped something like 

 a mole's foot, with the claws directed 

 downwards. The genus is best distin- 

 guished by the flower-spikes, which are 

 produced from the axils of the leaves, and 

 are divided into numerous very long tail- 

 like branches, clothed with two opposite 

 rows of overlapping spathes, each of which 

 encloses a short spike of flowers— the two 

 sexes being upon separate trees. Thefruits, 

 like those of all other Calamea,&re densely- 

 covered with overlapping scales, but the 



