POLYGALACEAE 
521 
Pogostemon Desf. Labiatae (vi. 12). 32 sp. Indo-mal., Japan. P. 
Patchouly Pellet yields the well-known perfume by distillation. 
Poinciana Tourn. ex Linn. Leguminosae (11. 7). 3 sp. trop. Afr. and 
As. P. regia Boj. is cultivated as an ornamental tree (Flamboyante). 
Foinsettia R. Grah. = Euphorbia Linn. 
Polanisia Rafin. = Cleome Linn. 
Polemoniaceae. Dicotyledons (Sympet. Tubiflorae). 8 gen. with about 
200 sp., chiefly N. Am.; a few in Chili, Peru, Eur., N. As. Herbs 
(rarely shrubby below), glabrous or shortly hairy, with usually opp. 
exstip. leaves. Firs, in cymes (sometimes condensed into involucrate 
heads), $ , regular or slightly zygomorphic, with or without bracteoles. 
K (5), valvate or imbricate, persistent; C (5), bell- funnel- or plate- 
shaped, usually convolute ; A 5, epipetalous, alt. with petals; G (3) or 
rarely (2 — 5), on a disc, multiloc. , with simple style more or less 
lobed at tip. Ovules 1 — 00 in each loc., anatropous, sessile. Fruit 
usually a loculicidal capsule. Embryo straight, in endosperm. Chief 
genera : Cobaea, Cantua, Phlox, Collomia, Gilia, Polemonium 
(mostly favourite border plants). Placed in Polemoniales by Benth.- 
Hooker, in Tubiflorae by Warming. 
Polemoniales (Benth. -Hooker). The 8th cohort of Gamopetalae (p. 
135)- 
Polemonium (Tourn.) Linn. Polemoniaceae. 14 sp. Eur., N. As., 
N. Am. P. caeruleum L. (Jacob’s ladder) in Brit., but rare. The 
honey is protected by hairs at the base of the sta. (cf. Hydrophylla- 
ceae). 
Polianthes Linn. Amaryllidaceae (11). 3 sp. Mexico. P. tuber osa L. 
(tuberose) is largely cultivated for its scented firs. 
Polyalthia Blume. Anonaceae (3). 70 sp. Old World trop. 
Polycarpicae (Warming). The 8th cohort of Choripetalae (p. 137)* 
Polycarpon Loefl. Caryophyllaceae (II. 3). 7 sp. temp, and subtrop. 
P. tetraphyllum L. (polycarp or allseed) in Brit. 
Polycnemum Linn. Chenopodiaceae ( r). 5 sp. Eur. The structure of 
the fruit is curious, a ridge developing at its apex after fertilisation. 
Polygala (Tourn.) Linn. Polygalaceae. 450 sp. cosmop. exc. N. Z., 
Polynes., and Arctic zone. A few have stipular thorns. P. vulgaris 
L. (milk-wort) is common on moors in Brit. The firs, owe their 
conspicuousness to the two coloured sepals; they occur in three 
colours, red, white, and blue, usually on different plants but sometimes 
on the same one. The essential organs in most sp. are contained in 
the keel and emerge from it, as in Leguminosae, when it is depressed 
by a visiting insect. P. Senega L. (Senega snake-root) in N. Am. is 
medicinal. 
Polygalaceae. Dicotyledons (Archichl. Geraniales). 10 gen. with 
700 sp., cosmop. exc. N. Z., Polynes., and Arctic zone. Herbs, 
shrubs, or small trees with simple entire alt. opp. or whorled usually 
exstip. leaves ; the stipules when present are usually thorny or scaly. 
