1284 



PETASITES 



PETUNIA 



singly. They are rather coarse and weedy, but the fol- 

 lowing are desirable for special purposes. 



P. fragrans, the Winter Heliotrope or Sweet Colts- 

 foot, has the merit of blooming in winter and its fls. 

 have a delightful vanilla-like odor. The fls. are small 

 and vary from pale lilac to purple. A few sprays are 

 desirable for cutting during winter. The plant also 

 differs from the common coltsfoot in having darker 

 colored and evergreen foliage. It is suitable for carpet- 

 ing shrubberies and for dry banks of stiff clay where 

 choicer subjects will not thrive. Like most others of 

 the genus, it spreads rapidly by underground runners. 

 This plant seems to be unknown to American commerce ; 

 the above points being taken from Gn. 23, p. 113, and 

 53, p. 328, where the plant is well pictured. 



P. palmata blooms from April to June, its fls. varying 

 from nearly white to pale blue or purplish. It is found 

 in rich dark swamps or sphagnum bogs from Newfound- 

 land to Alaska and south to N. Y., Wis. and Calif. It 

 has been offered by two dealers in native plants. 



P. Japonica, var. gigantea has recently appeared in 

 European and American garden literature. The cata- 

 logue of the Yokohama Nursery Company states that 

 the leaf-stalks grow 6 ft. high and 1-1% in. thick. The 

 stalks are eaten as a vegetable after being boiled, 

 and are also preserved in salt or sugar. The 

 flower-buds, which appear in February, are used 

 as a condiment, as they have a slightly bitter but 

 agreeable flavor. The plant has been advertised 

 in America since 1900 by several dealers. 



The genus is widely distributed in north tem- 

 perate and subarctic regions. The number of 

 species is uncertain, but the essential character 

 of the genus (as distinguished from Tussilago) 

 is that the heads are nearly or quite dioecious, 

 and rayless or with very short and not showy 

 rays; also the fact that the scapes usually have many 

 fls. instead of one. The Ivs. are orbicular or reniform, 

 always with a deep heart-shaped base and the scapes 

 are covered with scales like a coltsfoot but sometimes 

 the lower ones are more leafy. 



A. Size of Ivs. gigantic, 3%-4 ft, across. 

 . Japonica, F. W. Schmidt. Island of Sachaline. Var. 

 gigantea, Hort. Lvs. orbicular margin wavy. Sacha- 

 line Isl. Grows as high as a man 



AA. Size of Ivs. S-12 in. 

 B. Blooming December to MarcJi. 

 fragrans, Presl. WINTER HELIOTROPE. SWEET COLTS- 

 FOOT. Height 8 in. : Ivs. appearing during or after an- 

 thesis, orbicular, margined with small cartilaginous 

 teeth, glabrous above, pubescent and green below: 

 heads fragrant, the marginal fls. of the female heads 

 in the form of short rays. Mediterranean region. 



BB. Blooming April to June. 



palmata, Gray. Height 6-24 in. : Ivs. orbicular in out- 

 line, deeply 7-11-cleft beyond the middle, and the lobes 

 sharply dentate, green and glabrous above, densely 

 white-tomentose beneath : heads fragrant, 46 lines 

 across, the marginal fls. of the female heads in the 

 form of short rays. E. Asia, N. Amer. B.B. 3:469. 



W. M. 



PETREA (Robert James, Lord Petre", 1710-1742, a 

 patron of botany who had the finest collection of exotic 

 plants in Europe). Verbenacece. Petrea volubilis, or the 

 Purple Wreath, is one of the rarest, most distinct and 

 beautiful of tender climbers. The flower is like a 5-pointed 

 star of lilac with a good-sized violet in the middle. See 

 Fig. 1726, which indicates the graceful raceme 7-8 in. 

 long, containing perhaps two dozen flowers. The flowers 

 begin to open at the base of the raceme and the showy 

 5-pointed star is the calyx, whose sepals are colored 

 like petals. The calyx spreads open while the corolla 

 is still a round bud in the middle, and it remains after 

 the corolla has fallen, so that the vine, at first glance, 

 seems to bear two kinds of flowers. The blooms appear 

 in March and April. It should be in every greenhouse 

 collection, although it is of very irregular growth. It 

 does not bloom freely in small plants; it probably has 

 other drawbacks, for it has always been a rare plant in 

 Europe, though often enthusiastically commended. The 



fls. seem to vary considerably in color : The Purpie 

 Wreath is suitable for rafters. Propagated by cuttings 

 of dormant wood taken just before the new growth be- 

 gins. Give the cuttings bottom heat. 



Petrea is a genus of about 16 species of tropical 

 American twining or arborescent shrubs: Ivs. opposite, 

 leathery: fls. violet, purple or bluish in long, termi- 



1726. Petrea volubilis. 

 From a cluster 7 or 8 in. long. 



nal racemes; calyx-lobes colored during anthesis but 

 often becoming green in fr. ; corolla usually a little 

 more intensely colored; limb 5-cut, oblique; stamens 

 4, didynamous: ovary imperfectly 2-loculed; locules 1- 

 ovuled. 



volubilis, Linn. PURPLE WREATH. Fig. 1726. Lvs. 

 3-4 in. long, short-stalked, ovate, elliptic or oblong, acu- 

 minate or obtuse, entire or wavy. Cuba to Brazil. B.M. 

 826. F.C. 3:108. Gn. 12:82. 



G. W. OLIVER and W. M. 



PE-TSAI or Chinese Cabbage. Brassica Pe-Tsai. 



PETTERIA (after Franz Petter, a Dalmatian botan- 

 ist; died 1853). Leguminbsoe. Only one species, very 

 similar in habit to Laburnum, but with the yellow fls. 

 in upright dense racemes, terminal on leafy branchlets. 

 It is but rarely cultivated, since it is less showy in 

 bloom than Laburnum or many species of Cytisus. It 

 is probably hardy as far north as Mass., and requires 

 the same culture as Laburnum, which see. If grafted, 

 Laburnum is to be used as a stock. This monotypic ge- 

 nus is closely allied to Laburnum, but differs by its up- 

 right racemes, by the wings and keel being at the base 

 adnate to the stamens and by the sessile ovary. It is 

 said to possess the same poisonous properties as that 

 genus. 



ramentacea, Presl. (Cytisus frdgrans, Weld. C. 

 We"ldeni, Vis. Laburnum ramentdcenm, C. Koch). 

 Upright shrub, to 6 ft. : Ivs. 3-foliolate, almost glabrous 

 or sparingly pubescent when young, on about 1 in. long 

 stalks; Ifts. cuneate, obovate to oblong, usually obtuse, 

 %-2 in. long: fls. fragrant, very short-pedicelled, in 1-3- 

 in. long, dense racemes; calyx 3-lobed, silky; keel 

 silky: pod linear-oblong, sparingly silky, to 1% in. long. 

 May, June. Dalmatia, Istria. B.R. 29:40. 



ALFRED REHDEE. 



PETTIGREE, Pettigrue, or Butcher's Broom. 



ens aculeatus. 



Bus- 



PETtTNIA (South American aboriginal name, said to 

 have been applied to tobacco). Solandcea 1 . There are 

 twelve or more species of Petunia, mostly native of the 

 southern part of South America. One or two grow in 

 Mexico and another (P. parviflora) is naturalized in 

 the southern parts of the U. S. Petunias are small 





