386 



POM 



THE UNIVERSAL HERBAL; 



PON 



138. Polypodium Lunulatum. Fronds bipinnate; leaflets 

 pinnate, serrate at the tip, setaceous ; pinnas linear-oblong, 

 falcate, serrulate at the tip; stipe rough. Native of the 

 islands in the South Seas. 



139. Polypodium Latifolium. Fronds subbipirmate ; leaf- 

 lets ovate, acuminate, pinnatifid and lobed; segments repand 

 creuate ; stipe very smooth, shining. Native of the islands 

 in the South Seas. 



Polypody. See Polypodium. 



Polypremum ; a genus of the class Tetrandria, order 

 Monogynia. GENERIC CHARACTER. Calix : perianth 

 four-leaved, permanent; leaflets lanceolate, keeled, coloured 

 within. Corolla: one-petalled, wheel-shaped; limb four- 

 cleft; lobes obcordate, the length of the calix. Stamina: 

 filamenta four, very short, in the throat of the corolla ; 

 antherse roundish. Pistil: germen obcordate; style short, 

 permanent; stigma truncate. Pericarp: capsule ovate, com- 

 pressed at the tip, emarginate, two-celled, two-valved ; the 

 partitions contrary. Seed: numerous, fastened to an oblong 

 ascending receptacle, connected with the partition below. 

 ESSENTIAL CHARACTER. Calix : four-leaved. Corolla : 

 four-cleft, wheel-shaped, with obcordate lobes. Capsule: 



compressed, emarginate, two-celled. The only known 



species is, 



1. Polypremum Procumbens. Root annual ; stems pro- 

 cumbent; leaves linear, subulate, in whorls; peduncles one- 

 flowered, solitary, in the whorls of leaves ; flowers small, white. 

 Native of Carolina and Virginia. 



Polytrichum ; a genus of the class Cryptogamia, order 

 Musci. ESSENTIAL CHARACTER. Outer fringe, of thirty- 

 two, or sixty-four, short, flat, incurved teeth ; inner, a flat 

 transverse, orbicular, undivided membrane. Veil generally 

 double ; the outer hairy. There are sixteen British species, 

 besides foreign. The following are most worthy of notice. 



1. Polytrichum Commune; Common Hair-moss. Stem 

 simple ; leaves linear-lanceolate, finely serrated ; capsule 

 erect, quadrangular; pedestal roundish. It forms large tufts 

 of simple plants, matted together by the copious fibres of their 

 very long unbranched creeping roots. Common on boggy or 

 turfy groves or woods throughout Europe. 



2. Polytrichum Alpinum; Alpine Hair-moss. Leaves lan- 

 ceolate-awl-shaped, finely serrated; capsule ovate, drooping; 

 pedestal turbinate ; stem branched. Native of Alpine tracts 

 in Wales, Scotland, Switzerland, &c. 



Pomegranate. See Punica. 



Pometia; a genus of the class Monoecia, order Hexandria. 

 GENERIC CHARACTER. Male Flowers. Calix: peri- 

 anth one-leafed, wheel-shaped, six-cleft, very short; seg- 

 ments roundish. Corolla: petals six, orbicular, erect, a little 

 longer than the calix ; nectary a raised rim, with six little swell- 

 ings. Stamina : filamenta six, awl-shaped, erect, three times 

 as long as the corolla, placed on the margin of the nectary; 

 antherae parabolical, bifid at -the base. Pistil: rudiment in 

 the centre of the flowers. Female Flowers, in the same 

 raceme with the males. Calix and Corolla: as in the males. 

 Pistil: germen obcordate, twin, two-celled; style filiform, 

 four times as long as the corolla; stigma compressed. Peri- 

 carp: berry globular, fleshy, superior. Seeds: single, ovate, 

 in the centre of the berry. ESSENTIAL CHARACTER. Calix: 

 one-leafed, six-cleft. Petals: six. Male. Stamina: six. 



Female. Berry: globular, with one seed in the centre. 



The species are, 



1. I'ometia Pinnata. Leaves pinnate; raceme superde- 

 compound, terminating. Native of the South Sea islands. 



2. Pometia Ternata. Leaves ternate ; racemes almost 

 simple, axillary. The parts of fructification are not six as 



in the preceding, but two, and multiplies of that number. 

 Native of New Caledonia. 



Pommereulla ; a genus of the class Triandria, order 

 Monogynia. GENERIC CHARACTER. Calix: glume tur- 

 binate, three or four flowered, two-valved ; valves equal, 

 wedge-shaped, divaricate ut the base ; claw incurved, linear, 

 gradually widening, four-cleft ; segment dilated in a ring, 

 and involving the florets, unequal; the side ones larger, lan- 

 ceolate, acute; the inner or middle ones shorter by half, awl- 

 shaped, awned ; awn dorsal, inserted between the inner seg- 

 ments, solitary, straight, upright, larger than the valves. 

 Corolla : glume two-valved ; valves unequal ; the outer very 

 like the calicine glumes, awned ; the inner very short, quite 

 simple or undivided, ovate, flat, awnless. Stamina : fila- 

 menta three, very short; an there linear, the length of the 

 glumes. Pistil: germen linear ; style simple ; stigmas two, 

 villose at the side. Pericarp: none; corolla unchanged, 

 contains the seed till it is ripe, then gapes and lets it drop. 

 Seed : single, oblong, flat on the inner side, on the outer 

 convex, pellucid, very smooth. Observe. The flower resem- 

 bles the figure of the Dianthus, with a narrow tube, and n 

 spreading subradiate border ; for the florets in the centre of 

 the flower converge to a point. ESSENTIAL CIIARACTI u. 

 Calix: turbinate, two-valved, three or four flowered ; valves 

 four-cleft, awned at the back. Corolla: two-valved, awned. 

 The only species yet known is, 



1. Pommereulla Cormicopice. Root creeping, fibrous, 

 white; leaves equilant, imbricate, in two rows, compressed, 

 scarcely a finger's length, even ; culms branched, scarcely 

 longer than the leaves. It is a small and very singular Grass, 

 a few inches high. The flowers are spiked, each resembling 

 a little shuttlecock. Native of the East Indies. 



Ponipion. See Cucurbita. 



Pomnm. See Pyms. 



Poncca; a genus of the class Octandria, order Trigynia. 

 GENERIC CHARACTER. Calix: perianth one-leafed, 

 five-parted; segments roundish, concave, spreading. Co- 

 rolla: four, lanceolate, acute, with a few hairy glands at 

 the tip, longer than the calix, fastened to the annular recep- 

 tacle of the flower. Stamina: filamenta eight, capillary, 

 inserted into the same receptacle, alternate (opposite to 

 the petals larger, opposite to the corolla smaller,) the 

 length of the corolla; antherae ovate. Pistil: germen ob- 

 long, triangular, somewhat stalked; styles three, short; 

 stigmas acute. Pericarp : capsule three-celled, three-winged, 

 each wing two-valved. Seeds: solitary, ovate. ESSENTIAL 

 CHARACTER. Calix: five-parted, spreading. Petals: four, 

 with hairy glands at the tip. Germen : three-sided. Capsule: 



three-winged, three-celled, with one seed in each cell. 



The only species known is, 



1. Ponaea Guianensis. This is a tree, with a middle- 

 sized trunk of twenty feet high, and branched at the top 

 into three dimensions, each of which is garnished throughout 

 its whole length with leaves growing pretty near each other. 

 Leaves winged, of many pairs of unequal-sided, entire, veiny, 

 smooth leaflets, seven or eight inches in length. The flowers, 

 which are very small, and of a whitish colour, are produced 

 at the extremities of the branches on large spreading panicles; 

 they are sessile, and placed on the panicle in little approxi- 

 mating heaps. This tree is a native of Guiana, growing near 

 the borders of rivers ; fruiting and flowering in November. 



Pondweed. See Potamoyeton. 



Pontcderia; a genus of the class Hexandria, order Mono- 

 gynia. GENERIC CHARACTER. Calix: spathe common, 

 oblong, opening on the side. Corolla: one-petalled, two- 

 parted, tubular; upper lip straight, three-parted, outwardly 



