PERIPLO CA. 



208 



PETRiE'A. 



ligneous or herbaceous, every year ; 

 and this is sufficient to prevent trees 

 and shrubs in permanent plantations 

 from being injured : but from the 

 constant digging, &c, in a garden, 

 perennial herbaceous plants are very 

 seldom permitted to extend their roots 

 to a sufficient distance to find suitable 

 soil ; and they are therefore bene- 

 fited by taking up and replanting, or 

 laying down decayed leaves or fresh 

 soil over their roots. The season for 

 taking up and replanting pei'ennial 

 plants should be either in autumn 

 after they have done growing, or in 

 spring before they begin to grow; and 

 if the soil about the roots looks black 

 and saturated with moisture, or, as the 

 gardeners express it, "sour," the roots 

 should be washed quite clean before 

 replanting- Where the roots are to 

 be divided, it may be done, if they 

 are large, with the spade, or if they are 

 small with a knife ; and, at all events, 

 they should be cut smooth, and 

 trimmed (that is, all the bruised parts 

 removed) with a sharp knife, before 

 replanting. — See Planting. 



Pergula ria Asclepediacece.-- P . 



odoratissima has, perhaps, a sweeter 

 fragrance than any other plant known. 

 The flowers are green and of no pe- 

 culiar beauty, b ut th ey are mostval u able 

 for their delightful fragrance, which is 

 chiefly perceptible at night. The Per- 

 gularia is a stove-climber which should 

 be grown in a large pot (a 12) with holes 

 in the sides, which should be plunged 

 into the centre pit of the stove and kept 

 moist. The soil should be sandy loam or 

 chopped turf mixed with leaf-mould ; 

 andit is propagated by cuttings struck in 

 sand with bottom heat, and covered with 

 a bell-glass. It should becut back every 

 year when it has done flowering ; and it 

 will shoot out vigorously in Spring. 



Periplo^ca. — AsclepediacecB. — P. 

 grasca is a handsome hardy climber 

 with velvet-like flowers of a very sin- 

 gular colour, being a dark purplish 



maroon. It will grow in any light 

 rich soil, and it is very suitable for 

 covering arbours. It is said to be 

 fatal to flies, and that a number of 

 dead flies may be swept up every day 

 in bowers covered by it. It is a na- 

 tive of the Canary Isles, and it is 

 propagated by layers or cuttings, both 

 of which grow freely. 



Peri'skia. — Cactacece. — The Bar- 

 badoes or West India Gooseberry. 

 This plant bears very little resem- 

 blance to the other kinds of Cacti, 

 as it has thin leaves and a round stem 

 like any other iigueous plant. P. 

 aculeatus, the commonest kind, has 

 white flowers ; but the flowers of P. 

 Bleo are of a beautiful pink. The 

 fruit resembles a gooseberry and is 

 very good to eat. The Periskias are 

 quite hardy, growing in the same 

 temperature and requiring nearly the 

 same treatment as the Opuntia or 

 common Indian fig ; (see Opuntia;) 

 and P. aculeatus is frequently used 

 as a stock for grafting on it the more 

 tender kinds of Cacti. 



Periste^rea — OrchidacecB. — The 

 Dove Flower. Beautiful Peruvian 

 epiphytes, which should be grown on 

 wood. — See Orchideous Epiphytes. 



Periwinkle. — See Vinca. 



Perne'ttya. — Ericacece. — A 

 pretty little evergreen bush, a native 

 of Terra del Fuego, with white heath- 

 like flowers. It is quite hardy, and 

 only requires to be grown in a bed of 

 peat soil. 



Persica x ria. — See Polygonum. 



Petrje'a. — Verbenacece. — P. vo- 

 lubilis is a climbing plant with long 

 and beautiful racemes of dark purple 

 flowers, and large dark green leaves. 

 It is a native of Vera Cruz and Mar- 

 tinique, where it ascends to the sum- 

 mit of lofty treeSjhanging from branch 

 to branch in graceful festoons, and 

 producing its flowers in great abund- 

 ance. In England, though it has been 

 introduced since 1733, it is rarely 



