498 
OX Y GRA PHIS 
Oxygraphis Bunge. Ranunculaceae (3). 9 sp. N. temp. 
Oxylobium Andr. ( Callistachys Vent.). Leguminosae (ill. 2). 27 sp. 
Austr. 
Oxymitra Hook. f. et Thoms. Anonaceae (4). 50 sp. Old World trop. 
Oxypetalum R. Br. Asclepiadaceae (11. 2). 80 sp. Brazil, Mexico, 
W. Indies. 
Oxyria Hill. Polygonaceae (1. 2). O. digyna Hill, the only sp., in 
N. Arctic and subarctic regions (in Brit, an alpine plant). Like 
Rumex, but dimerous, and with ‘dedoublement’ of the outer sta. 
Oxytropis DC. Leguminosae (in. 6). 150 sp. N. temp. ; 2 in Brit. 
Pachira Aubl. Bombacaceae. 4 sp. trop. Am. United to Bombax in 
Nat. PJi . 
Pachyrhizus Rich. Leguminosae (in. 10). 2 sp. trop. Am., As., 
largely cultivated for the edible tuberous root (Yam-bean). 
Pachysandra Michx. Buxaceae. 2 sp. Japan, Alleghanies (cf. Epigaea). 
Padus Linn. = Prunus Tourn. 
Paederota Linn. Scrophulariaceae (ill. io). 2 sp. Mts. of Eur. 
(p. 149). 
Paeonia (Tourn.) Linn. Ranunculaceae (1). 15 sp. Eur., As., west 
N. Am. P. officinalis L. is the common Paeony, noteworthy for its 
tuberous roots, large firs, with great secretion of honey, slight cohesion 
of cpls., and follicle with red seeds. The protogynous firs, close at 
night. 
Paepalanthus Mart. Eriocaulaceae. 215 sp. S. Am., 1 N. Am., 
1 S. Afr. 
Palafoxia Lag. Compositae (vi). 7 sp. U.S. 
Palaquium Blanco ( Dichopsis Thw.). Sapotaceae (1). 50 sp. Indo- 
mal. P. Gutta Burck was formerly the chief source of gutta-percha, 
but it is now quite extinct except in cultivation, and the commercial 
article is obtained from other sp. and from Payena Leerii , &c. The 
trees are cut down or ringed and the milky latex coagulates, forming 
gutta percha (cf. caoutchouc). 
Palava Juss. (Palaua Cav.). Malvaceae (1). 3 sp. Chili, Peru. 
Palicourea Aubl. Rubiaceae (11. 1^5). 100 sp. trop. Am. 
Palisota Rchb. Commelinaceae. 8 sp. trop. W. Afr. 
Paliurus Tourn. ex Mill. Rhamnaceae. 2 sp., one, P. aculeatus Lam. 
(Christ’s thorn, cf. Zizyphus), S. Eur. to China, the other, P. ramo- 
sissimus Poir. in China and Japan. The former has stipular thorns, 
one straight, the other recurved; the latter has both thorns straight. 
The fruit has a horizontal wing, developed at the base of the style 
after fertilisation. 
Palmae. Monocotyledons (Principes). 128 gen. with 1100 sp. trop. 
and subtrop. ; most of the genera are well localised in the various 
floral regions, the chief exceptions being Cocos nucifera , Elaeis gui- 
neensis and Raphia vinifera . The palms form a characteristic feature 
of the vegetation of the tropics (pp. 155, 190). The vegetative habit 
