PERISTROPHE 



branches nearly horizontal, pubescent above: Ivs. 

 lanceolate, pointed at both ends: fls. sparse, in terminal 

 cymes, rose-colored. Flowers freely. Java. Var. afcrea 

 variegata, Hort.. has the center of the Ivs. variegated 

 with yellow. Useful for vases and baskets. 



HEIXRICH HASSELBRTNG. 



PERIWINKLE: Vinca. 



PERNETTYA (after A. J. Pernetty, 1716-1801; he 

 accompanied Bougainville on his voyage and wrote "A 

 Voyage to the Falkland Islands"). Ericaceae. Orna- 

 mental plants grown chiefly for their attractive vari- 

 ously colored and profusely produced berries, also for 

 their neat evergreen foliage and white or pinkish 

 flowers. 



Evergreen shrubs: Ivs. alternate, short-petioled, 

 small, usually serrate: fls. axillary, usually solitary on 

 slender nodding pedicels, rarely in racemes; calyx 

 5-parted; corolla urceolate, with short 5-lobed limb; 

 stamens 10, the anthers 4-awned at the apex: fr. a 

 5-celled many-seeded berry. About 25 species from 

 Mex. to the Magellan region, mostly in the mountains, 

 and 1 species in Tasmania and New Zeal. Allied to 

 Gaultheria, but the calyx not enlarged and rarely fleshy 

 after flowering. 



The pernettyas are low much-branched shrubs with 

 dense and small evergreen leaves and small nodding 

 flowers, followed by very decorative berries van-ing in 

 color from white to" purplish black or bluish black and 

 remaining on the branches all winter. These exceed- 

 ingly pretty shrubs are great favorites in England, but 

 are little known in this country. P. mucronata and P. 

 angustifolia. the hardiest, are probably hardy in 

 sheltered positions as far north as New York. They are 

 well suited for rockeries and borders of evergreen shrub- 

 beries and also make very handsome pot-plants. They 

 grow best in a peaty and porous moderate!}- moist soil 

 and prefer sunny positions, but seem to grow almost 

 as well in any other well-drained soil; in shade they will 

 not fruit so profusely as in the full sun. Propagation is 

 by seeds or by cuttings of half -ripened wood in sum- 

 mer under glass; also by means of layers and suckers, 

 mucronata, Gaud. (Arbutus mucronatus, Linn. f.). 

 Much-branched shrub, to 2 ft., with glabrous or spar- 

 ingly hairy branches: Ivs. almost 2-ranked, ovate to 

 ovate-oblong, spiny-pointed, serrate, dark green and 

 shining above, glabrous, H~^t m - long: fls. solitary, 

 nodding, globose-ovoid, white or slightly tinged pink, 

 about Vs'in. long, on pedicels 2-3 times as long as the 

 fl.; stamens longer than the ovary: fr. white to dark 

 purple, H~/^ m - across, red in the typical form. May, 

 June. Magellan region to Chile. "B.M. 3093; 8023. 

 B.R. 1695. L.B.C. 19:1848. Gn. 23:389; 59, p. 41. 

 Gt. 34, p. 214. G.M. 40:811. M.D.G. 1898:397. 

 Many varieties (P. hybrida, Zabel), partly originated 

 by hybridizing with the following species are cult, in 

 English and Dutch nurseries, mostly differing in the 

 color of the fr., which is usually indicated by the name 

 of the variety, as vars. alba," atropurpurea, coccinea 

 F.M. 1879:339), lilacina (F.M. 1879:339), nigra, 

 purpurea F.M. 1879:339), rosea, sanguinea, Hort. 

 Also P.Drummondii,P.Cummingii, P.speciosa, P.flari- 

 bunda (G.C. II. 18:649 and III. 28:465) belong here. 

 P. mucronata and its varieties are among our most 

 ornamental fruiting shrubs in wintertime, when they 

 are loaded with bright-colored berries contrasting well 

 with the dark glossy foliage; they are also very hand- 

 some in spring when covered with their numerous 

 white fls. 



angustifdlia, Lindl. (P. mucronata var. angustifolia, 

 Nichols.). Closely allied to the preceding: Ivs. lanceo- 

 late to linear-lanceolate, usually arched backward, 

 smaller, not spiny-pointed: fls. somewhat smaller, on 

 slender pedicels; anthers twice as" long as filaments; 

 style as long as ovary. May, June. Chile. B.R. 26:63. 



PERSEA 



2555 



B.M. 3889. The plant usually cult, under this name 

 is a narrow-lvd. form of the preceding species. 



P. ciliaris, Don. Spreading shrub: Ivs. oblong to narrow-oblong, 

 serrulate, 1 A-1 in. long: fls. solitary, ovate, white: fr. almost black. 

 Me , _p riUdri*, Lindl., not Don. J.H.S. 1851. p. 268. G.C. II. 

 10-89 and III. 28:463, belongs probably to P. furens. P. furens, 

 Klotrsoh. Upright shrub: Ivs. ovate to ovate-lanceolate, tiliate, to 

 1 U in. long: fls. in axillary, secund, rather dense racemes: fr. brown- 

 ish red. Peru, Chile. B.M. 4920. P. Pentlandii, DC. Similar to 

 P. mucronata, but Ivs. not spiny-tipped: fr. dark purplish blue, 

 with the calyx-lobes fleshy. Venesuela to Chile, B.M. 6.2O4. 

 P. phillyreiefdlia, DC. Similar to P. mucronata: branches spa- 

 ringiy hispid: corolla ovate, pubescent inside; anthers twice as long 

 as filaments. 'Peru, Chile. P. pildsa, Don (Arbutus pilosa, Gra- 

 ham). Prostrate shrub, with densely hispid branches: Ivs. elliptic- 

 oblong, serrate, to *iin. long: fls. ovate, white, solitary. Mex. 

 B.M. 3177. P. rupfcoJa, Phil. Closely allied to P. mucronata: Ivs. 

 smaller, with few minute teeth: fls. on pedicels scarcely twice as 

 long as fl.; stamens not exceeding the ovary. Chile. Sometimes 

 cult, as P. mucronata. P. rupicoloide*, Schneid. Supposed hybrid 

 of the preceding species and P. mucronata. 



ALFRED REHDER. 



PEROVSKIA (after B. A. Perovski, about 1840, gov- 

 ernor of the Russian province Orenburg). Also spelled 

 Perowskia. Labiate. About 4 herbaceous or shrubby 

 plants from Cent. Asia, allied to Salvia, with opposite 

 serrate or pinnatifid Ivs. and rather small heterostylous 

 fls. in whorls usually arranged in terminal spikes: calyx 

 tubular-campanulate, 2-lipped; corolla 2-lipped, the 

 upper lip unequally 4-lobed, the lower undivided; 2 

 sterile and 2 fertile stamens, the latter with 2 distinct 

 contiguous anther-cells: fr. consisting of 4 ovoid- 

 oblong nutlets inclosed by the calyx. The only species 

 in cult, is P. atriplicifdlia, Benth. Shrub, to 5 ft., erect, 

 of aromatic sage-like odor when bruised: sts. hoary- 

 tomentose: Ivs. ovate-lanceolate to lanceolate, acutish, 

 unequally and coarsely serrate, at first pubescent, 

 finally nearly glabrous, glandular, 1>-2K in. long: 

 fls. blue, about ^m. long, in 276-fld. remote whorls 

 arranged in slender spikes forming terminal panicles 

 1-1 H ft- long; calyx densely villous. Aug., Sept. 

 Afghanistan to W. Himalayas and W. Thibet. B.M. 

 8441. R.H. 1905:344. G. 33:511: 36:539 Handsome 

 shrub, valuable for its late blue fls. forming a pleasing 

 contrast with the silvery gray sts. Not quite hardy N., 

 but if killed partly back, it sends forth young shoots 

 which will flower the same year. It prefers sunny posi- 

 tions and well-drained loamy soil. Prop, is usually by 

 greenwood cuttings, which grow readily in summer 

 under glass. ALFRED REHDER. 



PERSEA (ancient Greek name of an Egyptian tree 

 with sweet fruit ; derivation unknown, probably from 

 Perseus). Lauracex. Woody plants sometimes grown 

 for ornament ; and one of them yields the avocado, one 

 of the best of the semi-tropical fruits. 



Leaves alternate, entire: fls. small, hermaphrodite, 

 usually in panicles; corolla wanting, the calyx deeply 

 6-parted; stamens usually 12, in 4 series, with one 

 series sterile; ovary sessile and tapering into a slender 

 style bearing a simple stigma. Shrubs and trees dis- 

 tributed throughout the tropics and subtropics, most 

 of the species being confined to S. Amer., but one com- 

 ing from the Canary Isls. and a few from S. E. Asia. 

 As defined by Bentham & Hooker, the genus contains 

 about 100 species, but Meissner (DC. Prodr. 15, pt. 1, 

 43) distributes some of the species in other genera and 

 retains only 50 in Persea. Mez, in his monograph on the 

 American Lauracese (Jahrb. Konigl. Bot. Gart. 1889, 

 5. 135), describes 47 American species. P. gratissima, 

 the avocado, widely cult, throughout Trop. Amer. and 

 elsewhere for its fir., is the only species of great eco- 

 nomic importance. Others are of ornamental value, and 

 may prove useful as stocks upon which to bud or graft 

 the avocado, although experiments have not been very 

 encouraging up to the present. P. Borbonia grows nat- 

 urally as far north as N. C.; P. indica is now and then 

 seen "in cult, in Fla. and Calif. Some of the Cent. 

 American types referred to P. gratissima seem distinct, 

 and may be found to constitute good species. 



