PYROLACEAE 
55 * 
officinalis L. (lung-wort, formerly officinal) and P. angustifolia L. in 
Brit. Both have dimorphic heterostyled firs, which change from red 
to blue as they grow older (see order). 
Pulsatilla (Tourn.) Linn. = Anemone Toum. 
Pultenaea Sm. Leguminosae (111. 2). 76 sp. Austr. 
Punica (Tourn.) Linn. The only genus of Punicaceae. 2 sp., one in 
Socotra, the other, P. Granatum L., the pomegranate, from the 
Balkans to the Himalayas, and cultivated in most trop. lands. The 
young twigs of the tree have four wings, composed simply of epidermis 
and cortical parenchyma ; these are early thrown off. The flr. is $ , 
regular, perigynous. K 5 — 8, valvate ; C 5 — 8, imbricate. Sta. 00 . 
Ovary adnate to receptacle. The mature ovary has a peculiar struc- 
ture, due to a development like that in Mesembryanthemum. Two 
whorls of cpls. with basal placentae are laid down, and then a peri- 
pheral growth tilts them up from || • (j to = . = so that two layers of 
loculi are formed and the placentation appears to be parietal. Ovules 
00 , anatropous. The arrangement is also seen in the fruit, commonly 
termed a berry, but not strictly so. The pericarp (axial in part) is 
leathery, and the fleshy inner part round the seeds is really the outer 
layers of the seed coats. 
Punicaceae. Dicotyledons (Archichl. Myrtiflorae). Only genus Punica 
(q.v.). Placed in Lythraceae by Benth. -Hooker and in Myrtaceae 
by Warming. 
Pupalia Juss. Amarantaceae (2). 5 sp. Afr., As. 
Purshia DC. Rosaceae (ill. 7). 1 sp. West U.S. 
Pusaetha Linn. = Entada Adans. 
Puschkinia Adams. Liliaceae (v). 2 sp. W. As. 
Pycnanthemum Michx. Labiatae (vi. n). 13 sp. N. Am. 
Pyrethrum Hall. = Chrysanthemum Tourn. 
Pyrola (Tourn.) Linn. (incl. Afoneses Salisb.). Pyrolaceae. 15 sp. N. 
Temp. (5 Brit, wintergreen). Evergreens with creeping stocks. P. 
(Afoneses) uniflora L. has adventitious buds on the roots, and a solitary 
terminal flower. P. minor L. is the most frequent in Brit. The firs, 
are in racemes, pendulous, without discs. There is no honey ; the 
stigma projects beyond the anthers, but pollen may at last fall upon it 
from them. P. rotundifolia L. is similar. The seeds of P. are very 
light and are distributed by wind. Many sp. prefer shady places. 
Pyrolaceae. Dicotyledons (Sympet. Ericales). 10 gen. with 30 sp., 
cold N. temp, and arctic. The two Brit, genera represent the two 
types of habit found in the order — evergreen plants with sympodial 
growth from rhizomes (Pyrola), and saprophytes (Monotropa). The 
infl. is terminal; it may be a true raceme (Pyrola), or a cyme, leafless 
or with scaly bracts. Fir. £ actinomorphic. K 4 — 5 ; C (4 — 5) or 
4 — 5; A 8 — 10, obdiplostemonous ; G (4 — 5). The petals and sta. 
are often at the edge of a nectariferous disc. Anthers introrse, opening 
by apical pores or transverse valves ; pollen simple or in tetrads 
