820 



VALLISNERIA-YIOLARIC^;. 



in the open ground, and increased by division or 

 seeds. 



VALLISNERIA (Linnaeus). A genus of Italian 

 and New Holland aquatics, of very curious character. 

 The flowers are dioecious, and belong to Hydrocharideas. 

 The European species grow in Italian ditches of con- 

 siderable depth. The female flowers are borne on long 

 spiral foot-stalks/and which rise and float on the surface 

 and there expand. The male flowers are produced 

 on a separate, and often a distant plant, and on very 

 short foot-stalks ; but when these are nearly ready to 

 bloom, they are detached from their mother plant, 

 and, ascending to the surface, float about among the 

 female flowers, where impregnation takes place. The 

 females, so soon as this takes place, again shrink to the 

 bottom to perfect the seed. The late Mr. Sweet 

 was of opinion, that these plants might be grown in 

 deep ponds in this country. 



VANESSA (Fabricius). A very extensive genus 

 of lepidopterous insects, belonging to the section 

 Diurna, or butterflies, and family Nymphalidce, having 

 the antennae terminated in a short abrupt club ; the 

 wings are angulated, the larvae very spinose, and the 

 chrysalis suspended by the tail without any girth 

 round the middle of the body. In this genus are 

 comprised some of our most splendid British butter- 

 flies ; the red admiral {V. Atalanta); the Cainberwell 

 beauty ( V. antiopa) ; the peacock ( V. io) ; the large 

 and small tortoise-shells (V. potychloros and Urticce); 

 and the comina ( V. C. album'), all belong to this genus. 

 They are, for the most part, of such common occur- 

 rence, as to render minute description unnecessary. 



VANILLA (Swartz). A genus of climbing orchi- 

 deous plants, natives of tropical America. One of these 

 is the old Epidendron vanilla of Linnaeus, the roots 

 of which are used for flavouring chocolate, and also 

 for perfuming snuff. They are grown in damp moss 

 in our stoves, and require a rough barked stump, or 

 a tree, or other support to climb upon. 



VELIA (Latreille). A genus of water bugs 

 (Hydrometridce\ having the legs formed for skimming 

 along the surface of water, of moderate length, and 

 placed at equal distances from each other. See 

 article INSECT, vol. ii., p. 842, figures 44, 45, for 

 representations of these insects. 



VERATRUM (Linnaeus). A remarkable genus 

 of hardy herbaceous plants, bearing potygarnous 

 flowers, and belonging to the natural order Melan- 

 thacecB. From the beauty of their foliage, and stately 

 spike of flowers, the species are worthy a place in 

 every flower-garden. They are increased by divi- 

 sion or by seeds, which must be sown as soon as they 

 are ripe. 



VERBASCUM (Linnaeus). A numerous genus 

 of biennial and perennial herbs, mostly natives of 

 Europe. The flowers are pentandrous, and the genus 

 belongs to Solanccc. The mulleins are well known 

 British hedge plants, though some of them are ad- 

 mitted into the garden. 



VERBENA (Linnaeus). A genus of annual, bien- 

 nial, and perennial herbs, chiefly natives of America ; 

 and their character is so peculiar, as to be taken as 

 the type of the order 



VERBENACE^E. Containing twenty-nine ge- 

 nera, and two hundred and seventeen species already 

 described in books. It is an order composed ol 

 plants of very various habits, lofty trees, and diminu- 

 tive herbs, bearing conspicuous or colourless flowers, 

 and with ample or attenuated foliage. The inflo- 



rescence is solitary or aggregate, spicate, capitulate, 

 or corymbiform, and both irregular and united : the 

 calyx is free, tubular, with a divided limb, and per- 

 sistent ; the corolla is hypogynous, tubular, with a 

 five-lobed limb, more or less irregular, and deciduous ; 

 the stamens four or five, didynamous, sometimes only 

 two exsertcd from the tube of the corolla, and alter- 

 nate with its lobes ; filaments are free, the anthers 

 adnate, two-celled, and bursting lengthwise by chinks ; 

 the germen is free, and formed of two connate 

 carpels ; the style one, and the stigma scarcely 

 divided. The vervain was a sacred plant, and in the 

 Druidical superstitions, was regarded with reverence. 

 To ancient superstitions is still owing its repute as a 

 medicine, as it was long esteemed as a potent ingre- 

 dient in love philtres. It is slightly bitter and astrin- 

 gent ; but its influence over disease or passion is 

 merely imaginary. V. Lambcrti, and V, aublctia, are 

 ornamental plants ; but the most useful in the order 

 is the famous Tectona Indica, or teak-tree of the ori- 

 ental forests. Its trunk is sometimes seen above two 

 hundred feet high, especially about Malacca and 

 the neighbouring islands ; and for ship-building is 

 almost equal to the oak. 



VERBESIN A (Linnaeus). A genus of shrubs and 

 herbaceous perennials, mostly natives of central Ame- 

 rica. Their flowers are mostly yellow, and belong to 

 Composite. Different species of Verbesina, according 

 to the country they come from, require the stove or 

 greenhouse, and some of them are hardy, grow tall, 

 and take their place in the shrubbery. 



VESPA (Linnaaus); VESPID^E, (Leach). The 

 wasp family. See WASP. The hornet is also one of 

 the large species of this genus, being systematically 

 under the name of Vespa crabro. 



VIBURNUM (Linnaeus). A genus of evergreen 

 and deciduous shrubs, natives of both North America 

 and Europe. They belong to the fifth class of Lin- 

 naaan botany, and to the natural order Caprifoliaccee. 

 The species are almost all ornamental shrubs, some of 

 them decidedly so, as the V. tintts, laurustine, and the 

 V, opulus, the guelder-rose. The V. nigosum, and 

 the V. odoratissimum, are greenhouse species, and 

 handsome plants. The hardy sorts are chiefly pro- 

 pagated by layers, the more tender sorts by cut- 

 tings. 



VICIA (Tournefort). A numerous genus of climb- 

 ing annual and perennial herbs, mostly natives of 

 Europe. The flowers are diadelphous, and the genus 

 belongs to Legnnrinosa:. Vetch is the common name 

 of this genus of plants. Several of them are useful 

 agricultural objects, being in most seasons the earliest 

 green forage that can be cut for cattle. 



VIOLA (Tournefort). This favourite genus 

 gives a title to Jussieu's natural order of 



VIOLARICE^E, and which comprises twelve ge- 

 nera, and one hundred and thirty-five species. The 

 greater part are hardy herbaceous plants, some of 

 which are attractive for their perfume, others for 

 their varied colours, and all for their neatness. The 

 generic character of Violaricece is expressed briefly 

 thus : apopetalous, angiospermous, dicotyledous, with 

 the sepals imbricate, and the petals obliquely con- 

 volute in aestivation ; the stamens equalling the 

 petals in number (five); the filaments elongated be- 

 yond the anthers, style one and undivided ; ovarium 

 one-celled, with narrow placenta, opening laterally ; 

 the seeds albuminous, the embryo erect, and the 

 leaves furnished with stipules. 



