921 



Oje Ercatfurp at 2Sfltang. 



[port 



POREWORTS. Lindley's name for the 

 Tremandracece. 



PORI (adj. POROSE). Apertures in the 

 covering of anything; as in the anthers 

 for the emission of pollen (hence poran- 

 drous), or in the skin, when they are also 

 called stomates. Also, appendages of the 

 pileus among fungals in the form of cylin- 

 drical or angular tubes, placed side by side, 

 open at one" end, and containing in their 

 cavity the organs of reproduction. 



PORILLON. (Fr.) Narcissus poeticus. 



PORION. (Fr.) Narcissus poeticus and 

 N, Pseudo-Narcissus. 



PORLIERA. A genus of shrubs of the 

 Zygophyllaceo?, named in honour of a Span- 

 ish botanist. The species are met with in 

 Peru and Chili. Their pinnate leaves are 

 provided with small spiny stipules ; the 

 flowers grew in tufts, and have a four- 

 parted calyx, four petals, eight stamens 

 inserted below into a little scale, and a 

 fonr-lobed ovary placed on a short stalk, 

 with four ovules in each of the four com- 

 partments; fruit fleshy, four-lobed, each 

 compartment containing but a single seed, 

 owing to the suppression of the remaining 

 three, P. hygrometrica is grown in this 

 country as a stove shrub. Its specific name 

 is given in allusion to the power that the 

 linear leaflets have of expanding in fine 

 and closing in wet weather. [M. T. M.] 



POROPHYLLUM. A genus of Composites 

 of the tribe Heliantliece, allied in many 

 respects to Tagetes and Pedis. It consists 

 of from twelve to fifteen South American 

 herbs or undershrubs, all glabrous and 

 more or less glaucous, with entire or tooth- 

 ed leaves almost always marked with pel- 

 lucid oblong glands. The flower-heads, al- 

 ways without rays, are singly pedunculate, 

 with tubular involucres of five often united 

 bracts. The florets are tubular, the style- 

 branches linear nearly as in Vernoniacea?. 

 and the achenes elongated as in Tagetes, 

 with a pappus of simple bristles. 



PORPHYRA. A genus of Ulvacece, with 

 a membranous flat frond, and dark-purple 

 spores arranged in fours, though its natu- 

 ral affinities are clearly with the green- 

 spored Algce. The species have undoubt- 

 edly been multiplied needlessly, and P. vul- 

 garis and P. laciniata, which supply the 

 Laver of commerce, run manifestly into 

 each other, though extreme forms seem 

 distinct. When very young they closely 

 resemble Bangice. The tint varies from a 

 clear rose to a livid purple, but though 

 occasionally slightly olivaceous is never 

 green. [M. J. B.j 



PORPHYREUS. Brown, mixed with red; 

 a warm red. 



PORPHYROCOMA. A genus of Acantha- 

 cea?, containing a single species, a shrub- 

 by plant, with opposite lanceolate almost 

 sessile leaves, and sessile flowers in ter- 

 minal aggregate spikes, which have a very 

 showy appearance from their large crowd- 

 ed purple bracts. The small calyx consists 



• of five subulate sepals, placed within three 

 i bracts, the outer one being very large ; the 

 corolla is tubular and two-lipped, the upper 

 | lip erect and two-lobed, the lower reflexed 

 j and three-lobed ; there are two stamens, 

 with anthers having two diverging cells; 

 and the ovary is surrounded by a disk, and 

 j bears a long slender style and obtuse stig- 

 I ma. The fruit, concealed by the large per- 

 sistent bracts, is unguiculate two-celled 

 and two-valved. There are four flattened 

 seeds on hooked retinaculaa. [W. C] 



PORTE-BANDEAU. (Fr.) Spargano- 

 vhcrus Vaillantii. 



PORTE-CHAPEAU. (Fr.) Paliuras acu- 

 leatus. 



PORTE-COLLIER. (Fr.) Osteospermum 

 moniliferum. 



PORTE-FEUILLE. (Fr.) Asperugo pro- 

 cumbens. 



PORTE-NOIX. (Fr.) Caryocar. 



PORTE-SUIF. (Fr.) Stillingia. - 



PORTLANDIA. The Duchess of Port- 

 ' land, a great lover of Botany, is comme- 

 morated by this very handsome genus of 

 cinchonaceous shrubs. The species are 

 j West Indian, and have elliptical leaves 

 with broad triangular stipules ; and very 

 j large whitish flowers, borne on axillary 

 flower-stalks, in groups of two or three. 

 I The limb of the calyx is divided into five 

 ] persistent leafy segments ; corolla funnel- 

 shaped, with a five-angled tube, and a limb 

 divided into five blunt lobes; stamens at- 

 tached to the throat of the corolla ; style 

 thread-like, as long or longer than the tube 

 of the corolla; stigma undivided ; capsule 

 ribbed, surmounted by the limb of the ca- 

 lyx and bursting from above downwards, 

 through the middle of the valves ; seeds 

 •numerous, rough. Some of the species 

 ! possess properties similar to those of the 

 true cinchona. The bark of P. hexandra 

 is used instead of cinchona in French 

 Guiana ; and that of P. grandiflora is ex- 

 ceedingly bitter. Two or three species are 

 in cultivation as hothouse plants, and 

 their splendid flowers are very ornamental ; 

 P. grandiflora is the one commonly met 

 with. P. platantha, a species of more re- 

 cent introduction, flowers in a dwarf state, 

 and is almost always in bloom— two great 

 recommendations. [M. T. M.] 



PORTLAND-POWDER. A medicine 

 consisting of equal parts of the roots of 

 Aristolochia rotunda and Gentiana lutea. 



PORTULACACE^I. (Purslanes.) A natu- 

 ral order of calycifloral dicotyledons belong- 

 ing to Lindley's silenal alliance of hypogy- 

 nousExogens. They are succulent shrubs 

 or herbs, with alternate seldom opposite 

 exstipulate leaves ; sepals two, cohering; 

 petals usually five, rarely wanting; stamens 

 usually perigynous, ovary free or partially 

 adherent, formed by three united carpels ; 

 j stigmas several. Fruit capsular, one-celled, 

 I opening by circumscissile dehiscence, or 

 by three valves,occasionally monospermous 



