ptjer] 



El)c t&vzxSmvi at Matmg. 



936 



or slightly five-toothed calyx limb ; a fun- 

 nel-shaped corolla with a regular tube, and 

 a spreading or reflected flve-lobed limb; 

 five stamens, concealed within the corolla 

 or slightly protruding; and a fleshy fruit 

 surmounted by the calyx, and having two 

 smooth or ribbed stones. The flowers are 

 mostly in terminal panicles. Several spe- 

 cies are in cultivation ; the flowers of most 

 of them are white or yellowish, and of no 

 great beauty. One is said to grow upon 

 trees as an epiphyte. Emetic properties 

 are assigned to the roots of some of the 

 species, especially to those of P emetica, a 

 Peruvian plant, which furnishes what is 

 called Striated Ipecacuanha, a substance 

 less valuable than the true ipecacuanha. 

 The roots of P. tinctoria and P. sulphured 

 have been used as dyes. [M. T. MJ 



PT^EROXYLON utile, a small timber 

 tree about thirty feet high, a native of the 

 Cape of Good Hope,is the only plant belong- 

 ing to this genus of Sapindacece. It has 

 pinnate leaves, composed of five or seven 

 pairs of thick unequal-sided entire leaflets, 

 with or without a terminal one ; and axil- 

 lary bunches of flowers, which are uni- 

 sexual by abortion, and have a calyx of 

 four sepals, four petals without appendages, 

 four free smooth stamens, and a two-celled 

 flattened ovary, bearing two distinct or 

 united styles, and two round-headed stig- 

 mas ; and its ripe fruit contains two winged 

 seeds, one in each cell. The timber of 

 Ptceroxylon is handsome, durable, and takes 

 a good polish, and is used at the Cape for 

 making articles of furniture and agricul- 

 tural utensils. It is called Nieshout or 

 Sneezewood by the Dutch colonists, from 

 its possessing the property of causing the 

 sawyers to sneeze violently when employed 

 upon it. On account of its not being 

 much affected by moisture, it is used 

 for mill-work and bridges; and it is said to 

 burn readily, even when green. [A. S.] 



PTARMICA. A genus proposed for the 

 Achillea Ptarmica, and some other large- 

 flowered chiefly alpine species, which differ 

 from the others in some very trifling cha- 

 racters. 



PTELEA. The Greek name for the elm, 

 and applied by Linnaeus to a genus of 

 shrubs or small trees, natives of North Ame- 

 rica and Asia, and included in Xantho.ru- 

 lacece. It may be briefly characterised by 

 Its monoecious flowers, which have a four 

 to five-parted calyx, four to five petals, 

 and in the male flowers as many stamens ; 

 in the female flowers, the two to three- 

 celled ovary is placed on a short stalk. 

 The fruit is turgid in the centre, and sur- 

 rounded by a broad membranous wing, 

 like that of the fruits of the elm. 



P. trifoliata, the Shrubby Trefoil of North 

 America, is frequently grown in shrub- 

 beries in this country. Its leaves are of a 

 rich green colour, with three unequal leaf- 

 lets. In autumn these leaves assume a 

 fine yellow tinge. The flowers are greenish, 

 arranged in corymbs less conspicuous than 

 the curious winged fruits, which ripen in 



October. In Canada the young green 

 shoots are used as an anthelmintic in the 

 form of infusion. Thefruits are bitter and 

 aromatic, and have been used as a substi- 

 tute for hops. [M. T. M.] 



PTE RANDRA. A genus of MalpigMacece, 

 consisting of tropical American shrubs, 

 with large stipules in the axils of the 

 leaves. Flowers pink, variously disposed 

 towards the end of the branches, their 

 stalks jointed and provided with two small 

 bracts, five-parted ; petals nearly regular, 

 stamens ten, all fertile, one or sometimes 

 both sides of the anthers expanded into a 

 crest-like appendage— whence the name of 

 the genus ; ovaries three, slightly adher- 

 ent ; styles three. [M. T. M.] 



PTERIDOGRAPHIA. That part of Bo- 

 tany which treats of Ferns. 



PTERIDOPHTLLUM. A genus of Fu- 

 mariacecB, comprising astemlessherbfrom 

 Japan, with a thick prajmorse rhizome, pec- 

 tinate-pinnatisect stalked leaves with scaly 

 petioles and numerous linear-oblong sub- 

 falcate segments (the terminal one three- 

 lobed), and; racemose flowers. Calyx two- 

 sepaled, deciduous ; petals four, the two 

 outer ones folded, the inner plain ; sta- 

 mens four; ovary orbicular, compressed, 

 one-celled; style filiform, with a capitate 

 two-lobed stigma. [J. T. SJ 



PTERIS. A genus of polypodiaceous 

 ferns typical of the Pteridece. It is known 

 by having linear marginal sori, on a con- 

 tinuous linear receptacle, and covered by 

 a membranaceous indusium of the same 

 form, combined with free veins. The 

 plants vary greatly in size and form, some 

 having pedate and others decompound 

 fronds ; and they are distributed over the 

 temperate and tropical regions, though 

 most plentiful in the latter. In the true 

 species the vernation is terminal ; but in 

 P. aquilina, the Common Bracken, not 

 only is the vernation lateral, but the 

 indusium is double ; that is to say, the 

 spore-cases lie between two— an inner 

 and an outer membrane. Hence it is not 

 improbable that this species will have to 

 be eventually removed. See P^esia. 

 The Bracken is the badge of the Robert- 

 sons. [T. M.] 



PTERIS. In Greek compounds = a wing 

 or membranous expansion. 



PTEROCARPTJS. "With the exception of 

 one South African species, this genus of 

 Legnminosce is confined within the tropics, 

 but has representatives in Asia, Africa, 

 and America. The fifteen described species 

 are all trees, frequently of large size, and 

 have alternate pinnate leaves with alter- 

 nate or irregularly opposite leaflets, and 

 simple racemes or loose panicles of showy 

 yellow flowers, which have a five-toothed 

 somewhat two-lipped calyx narrowed or 

 top-shaped at the base, anda papilionaceous 

 corolla with glabrous petals, and contain 

 ten stamens united into a sheath, which is 

 split on the upper or both sides (.some- 

 times nine are united and one free), and an 



