PSTLOTACEAE 
547 
facing the base of the ovary. The style is terminal, long, often 
bent inwards. Fruit a follicle, capsule, drupe or nut. Seed ex- 
albuminous. The ovary is sometimes borne on a gynophore and at 
its base are commonly nectarial outgrowths. The firs, are protandrous 
and adapted to insect-fertilisation. 
Classification and chief genera (see discussion in Nat. Pfl . ). 
I. PERSOONIOIDEAE (firs, single in axils of bracts; 
ovules seldom few or 2 ; drupe or nut, one seeded): Persoonia, 
Protea, Leucadendron. 
II. GREVILLOIDEAE (firs, in pairs ; ovules several or 2; 
fruit usually dehiscent and many seeded) : Grevillea, Hakea, 
Banksia. 
[Placed in Daphnales by Benth.-Hooker, in Thymelaeinae by 
Warming.] 
Proteales. The 10th cohort of Archichlamydeae (p. 127). 
Protium Burm. f. Burseraceae. 50 sp. trop. Am. Some yield 
resins. 
Prunella Linn. {Prunella Tourn.) Labiatae (vi. 4). P. vulgaris L. 
(self-heal) is cosmop. (incl. Brit.), the other 5 sp. Medit. Eur. The 
fruiting calyx is closed and points upwards in dry air, but opens and 
stands horizontally in damp. 
Prunus (Tourn.) Linn. (incl. Amygdaltis Tourn., Cerasus Tourn.). 
Rosaceae (v. 12). 75 sp. N. temp.; a few trop. P. msititia L. 
(bullace), P. spinosa L. (sloe or blackthorn), P. Avium L. (gean), 
P. Padus L. (bird-cherry), in Brit. The fir. -buds are laid down in 
August or September of the preceding year. There is 1 cpl., which 
gives rise to a drupe, while the hollow receptacle usually falls away. 
Many sp. are cultivated for their fruit, e.g. P. Armeniaca L. (apricot), 
P. domestica L. (plum, prune), P. A??iygdalus Stokes (almond), P. 
Persica Stokes (peach, with its smooth-fruited variety the nectarine), 
P. Cerasus L. (cherry), &c. P. Laurocerasus L. is the cherry laurel; 
it has extra-floral nectaries (p. 114) on the backs of the leaves, showing 
as brownish patches against the midribs. The spines of some sp. are 
axillary, as in Crataegus. 
Psamma Beauv. = Ammophila Host. 
Pseuderanthemum Radlkf. Acanthaceae (iv. B). 60 sp. trop. 
Pseudolarix Gord. Coniferae (1. 1 b). 1 sp. P. Kaempferi Gord., 
the golden pine, China. Like Larix, but distinguished chiefly by the 
deciduous fruit-scales. 
Pseudotsuga Carr. = Tsuga Carr. 
Psidium Linn. Myrtaceae (1). 100 sp. trop. Am. Many yield edible 
fruit, e.g. P. Guajava L., the guava. 
Psilotaceae. Lycopodinae (Homosporous). Two genera (Psilotum, 
Tmesipteris) with 3 sp. trop. and subtrop. The mature sporophyte 
has no roots, their functions being performed by the branched rhi- 
zomes. The aerial branches bear crily scale-leaves in Psilotum. The 
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