PERGULAEIA. 



230 



PETB^A. 



and this is sufficient to prevent trees 

 and shrubs in permanent jjlantations 

 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 there- 

 fore benefited by taking up and 

 replanting, or laying down decayed 

 leaves or fresh soil over their roots. 

 The season for taking up and re- 

 planting perennial 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. \Yhere 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. 



Peegula'eia. — Asdeinadece. — 

 P. odoratlssima has, perhaps, a 

 sweeter fragrance than any other 

 plant known. The flowers are 

 green, and of no peculiar beauty, 

 but they are most valuable for their 

 delightful fragrance, which is chiefly 

 perceptible at night. The Pergu- 

 laria is a stove-climber which should 

 be grown in a large pot (a 12) Avith 

 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 ; and 

 the plant is propagated by cuttings 

 struck in sand with bottom-heat, 

 and covered with a bell-glass. It 

 should be cut back every year when 

 it has done flowering ; and it will 

 shoot out vigorously in spring. 



Peki^ploca. — Asclepiadece. — P. 

 grc^ca is a handsome hardy climber, 

 with velvet-like flowers of a very 

 singular colour, being a dark pur- 

 plish maroon. It will grow in any 

 light rich soil, and it is very suit- 

 able 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 native of the Canary 

 Isles, and it is propagated by layers 

 or cuttings, both of which grow 

 freely. 



Pere'skia. — Cadacece. — The 

 Barbadoes or West Indian Goose- 

 berry. This plant bears very little 

 resemblance to the other kinds of 

 Cacti, as it has thin leaves and a 

 round stem like any other ligneous 

 plant. P. aculeata, the commonest 

 kind, has white flowers ; but the 

 flowers of P. Bleo are of a beautiful 

 pink. The fruit resembles a goose- 

 berry, and is very good to eat. The 

 Pereskias are quite hardy, growing 

 in the same temperature and re- 

 quiring nearly the same treatment 

 as the Opuntia or Common Indian 

 Fig (see Opu'ntia) ; and P. acule- 

 ata is frequently used as a stock for 

 grafting on it the more tender kinds 

 of Cacti. 



Periste'ria. — Orchidacece. — 

 The Dove Flower. — Beautiful Peru- 

 vian epiphytes, which should be 

 grown on wood. — See Orchideous 

 Epiphytes. 



Periwinkle. — See Vi'nca. 



Perne'ttia. — Encacece. — A 

 pretty little evergreen bush, a na- 

 tive 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. 



Persic a'ri A. — See Poly'gonum. 



Petr^^a. — Verbenacece. — P. 

 voluhilis is a climbing plant with 

 long and beautiful racemes of dark- 

 purple flowers, and large dark -green 



