VIOLA 



ViOLA (classical name). I'iol&cece. Violet. There 

 are probably 150 species of Violets. They are widely 

 distributed perennial or rarely annual herbs (or even 

 subshrubs) with interesting irregular flowers on 1- or 

 2-flowered axillary peduncles. They are plants of the 

 northern and southern temperate zones. About 40 spe- 

 cies are native to North America north of Mexico. The 

 flowers are 5-merous as to envelopes and stamens : 

 sepals all similar, persistent with the fruit: corolla 

 irregular, the lower petal spurred, the others similar 

 but usually not alike ; stamens short and included, the 

 anthers more or less coherent and two of them with an 

 appendage projecting into the spur : fr. a capsule, 

 3-valved, with several to many globular seeds. Some 

 of the species (particularly the common eastern V.pal- 

 mata) have cleistogamous flowers, which are borne at 

 the base of the plant (often under the mold) and are 

 pollinated in the bud. The structure of the corolla of 

 the Violet is shown in Fig. 2681. In Pig. 2682, repre- 

 senting the same species, the cleistogamous flowers are 

 shown at a a. 



Three species of Viola are well known in gardens. 

 The Common Sweet Violet is V. odorata. From this 

 the florists' Violet, in many forms, has been evolved. 

 The Pansy is V. tricolor. See Pansy. The Horned or 

 Butterfly Violet is V. cornuta. These are all European 

 species, and are cow considerably modified by cultiva- 

 tion. 



Many of the native Violas are offered by dealers in 

 hardy plants, but only V. pedata and V. pa Imata (with 

 its var. cucullata) are really known to any extent as 

 garden plants; and even these are not frequently seen. 

 V. pedata, the Bird's-foot Violet, is a most worthy spe- 

 cies, and it will some day, no doubt, be the parent of an 

 important garden race. It is very variable even in the 



VIOLA 1941 



Greene and others, and, moreover, the kinds are so 

 many, they are not described in this account; but a list 

 of those which are or have been offered in the trade is 



2681. The structure of the corolla of Viola palmata 

 var. cucullata. Somewhat enlarged. 



wild state. Since the native species are really not hor- 

 ticultural subjects, and the descriptions of them are so 

 easily accessible in the writings of Gray, Britton, 



2682. The two kinds of Violet flowers.— the common showy 

 flowers at the right, natural size, and the cleistoga- 

 mous flowers at a a (X %). Viola palmata var. cucullata. 



given below as a matter of record. In the nomencla- 

 ture of this list, the monograph of Gray has been fol- 

 lowed (Gray's Syn. Flora, vol. 1, pp. 195-204). 



Violets are easy to grow, particularly if an effort is 

 made to imitate the conditions under which they natur- 

 ally occur. Some of them are woods species, others 

 swamp species, and others inhabit dry plains. They 

 are propagated readily by means of division and in 

 some species by runners. Sometimes seeds are used, 

 but not commonly. Many species that grow mostly to 

 single stems in the wild make large full clumps when 

 given good opportunity in the garden. Fig. 2683. 



A. Plant perennial. 



B. Spur short and obtuse. 



hederacea, Labill. {JSrpetion renifdrme, Sweet. E. 

 hederaceum, petiolare and spathuldtitm, G. Don). Aus- 

 tralian Violet. 

 Tufted, and creeping 

 by stolons, glabrous 

 or pubescent : lvs. 

 reniform or orbicular 

 or spatulate, small, 

 entire or toothed, 

 usually not equaling 

 the scapes : fls. small, 

 usually blue, some- 

 times white, the spur 

 almost none. Aus- 

 tralia. —Offered in S. 

 Calif. 



odorata, Linn. Sweet Violet. Pigs. 2684, 2688-90. 

 Tufted, somewhat pubescent, producing stolons: root- 

 stock short: lvs. cordate-ovate to reniform, obtusely 

 serrate, the stipules glandular: fls. blue, fragrant (run- 

 ning into white and reddish purple forms), the spur 

 nearly or quite straight and obtuse. Eu., Afr. and 

 Asia. — It runs into many forms, varying in stature, 

 size of flowers and color. There are double-flowered 

 forms. The parent of florists' Violets. 



bb. Spur long and acute. 



cornuta, Linn. Horned Violet. Bedding Pansy. 

 Plant tufted, glabrous or nearly so, producing evident 

 stems with long peduncles in the leaf-axils : lvs. cor- 



2683. Clump i 



let of the eastern states. — Viola 

 palmata, var cucullata. 



