PEUCEDANUM 
5 2 3 
Perilomia H. B. et K. Labiatae (vi. 2). 8 sp. Andes. 
Periploca Tourn. ex Linn. Asclepiadaceae (1. 1). 12 sp. As., Afr., 
S. Eur. 
Peristeria Hook. Orchidaceae (19). 5 sp. Cent. Am. Epiphytic. 
P. elata Hook. (‘ el spirito santo,' so called by the natives of Panama 
because of its resemblance to a dove) is best known. Its mechanism 
requires investigation. 
Peristrophe Nees. Acanthaceae (iv. B). 20 sp. palaeotrop. 
Peristylus Blume = Habenaria Willd. 
Pernettya Gaudich. Ericaceae (11. 5). 26 sp., one Tasmania and 
N. Z., the rest S. Am. and Mexico. 
Perotis Ait. Gramineae (ill). 5 sp. palaeotrop. 
Persea Plum, ex Linn. Lauraceae (1). 25 sp. trop. Am. The fruit of 
P. gratissuna Gaertn. f. is eaten under the names Aguacate, Avocado, 
Alligator pear, Palta, &c., in most trop. countries. 
Persicaria (Tourn.) Linn. = Polygonum Tourn. 
Personales (Benth. -Hooker). The 9th cohort of Gamopetalae (p. 135). 
Personatae (Warming). The 5th cohort of Sympetalae (p. 137). 
Persoonia Sm. Proteaceae (1). 60 sp. Austr., N. Z. 
Pescatorea Rchb. f. = Zygopetalum Hook. 
Petalostemon Michx. ( Kuhnistera Lam.) Leguminosae (111. 6). 
20 sp. N. Am. 
Petasites (Tourn.) Linn. Compositae (vm). 14 sp. N. temp. P. 
officinalis Moench, the butter-bur, is common in Brit, on the banks 
of streams, &c. It spreads very largely by rhizomes. It is dioecious 
(cf. Tussilago, its close ally). The male head has about 30 firs, with 
the usual mechanism of Compositae, the style acting as the pollen- 
presenter, though the ovary is no longer fertile. Occasionally a few 
5 firs, are found. The female head consists of about 150? firs, sur- 
rounding 1 — 3 <? firs. Only the male firs, secrete honey. Under the 
name of winter heliotrope, P. fragrans Presl is cultivated for its 
scented firs., which appear in February. 
Petiveria Plum, ex Linn. Phytolaccaceae. 1 sp. Am. 
Petrea Houst. ex Linn. Verbenaceae (11). 12 sp. trop. Am., W. Ind. 
Petrophila R. Br. Proteaceae (1). 35 sp. Austr. 
Petrophyes Webb et Berth. = Monanthes Plaw. 
Petroselinum Hoffm. = Carum Linn. 
Petunia Juss. Solanaceae (iv). 14 sp. S. Am. P. violacea Lindl. 
and others are often cultivated in gardens. 
Peucedanum (Tourn.) Linn. (incl. Anethum Tourn., Imperaioria Linn. 
Paslinaca Linn.). Umbelliferae (7). 120 sp. Eur., As., Air., Am.; 
4 in Brit., of which P. (Past.) sativwii Benth. et Hook. f. is the 
parsnip, often cultivated for its fleshy roots. P. (A.) g)'aveole 7 is 
Benth. et Hook. f. (Medit.) is the dill, whose fruits are used as a 
condiment ; P. officinale L. (Brit.) is the sulphur-root, used in veteri- 
nary practice ; P. (/.) Ostruthiu 7 n Koch (Brit.) is also used. 
