valusne'ria. 



296 



vallisne'ria. 



europcea, the common kind, in fa- 

 vourable situations will grow ten feet 

 high. U. stricta, the Irish Furze, 

 has no spines, and it grows straight 

 upright to the height of eight feet or 

 ten feet. It requires a moist rich 

 soil ; and it is propagated by cuttings 

 like the double-blossomed kind, as it 

 has never yet been known to ripen 

 seeds. All the other kinds are pro- 

 pagated by seeds, which they ripen in 

 great abundance. 



Ulmus. — Ulmacece. — The Elm . 

 The weeping Elm is a very ornamen- 

 tal tree for pleasure-grounds. 



Umbilicus. — Crassulacece. — The 

 new name for some of the kinds of 

 Navelwort. — See Cotyledon. 



Umbrella Tree. — Magnolia tri- 

 petala. — See Magnolia. 



Ure v do. — Cryptogamia. — A kind 

 of rust often found on the leaves of 

 Rose Trees and other plants. — See 

 Mildew. 



Urtica. — Urticacece. — The 

 Nettle. The Roman Nettle, U. pi- 

 lulifera, is sometimes grown in gar- 

 dens as an ornamental annual, but 



the sting is much worse than that of 

 U. dioica, the common Nettle. 

 Some of the exotic species are very 

 handsome ; as for example, U. reti- 

 culata, a native of Jamaica, which has 

 red and yellow flowers and deep green 

 leaves. All the Nettles thrive most 

 in a deep rich soil. 



Us'nea. — Cryptogamia. — A kind 

 of lichen that hangs down like a 

 beard from the hranches of old trees, 

 particularly Oaks, and has a very pic- 

 turesque appearance. 



Uvula x ria. — Melenthacece. — Pe- 

 rennial hardy plants with pale yellow 

 flowers, natives of North America, 

 which should he grown in a compost 

 of peat and loam ; a pit about a foot 

 square every way, being dug in the 

 open border and filled with the com- 

 post to plant them in. If the sub- 

 soil be not good, the pit may be made 

 a little deeper, and a layer of stones 

 and brickbats may he put in the bot- 

 tom. The plants are propagated by 

 suckers, which they produce in great 

 abundance. 



V. 



Vacci'nium. — Ericaceae. — The 

 Whortle Berry. Dwarf shrubs with 

 pretty drooping heath-like flowers, 

 and generally showy fruit ; found ge- 

 nerally wild on commons in Europe 

 and North America. V. myrtillus, 

 the common Bilberry, is the com- 

 monest species in England, and there 

 is a variety with white berries in Ger- 

 many. The Cranberry, V. oxycoc- 

 cus, Lin., is now called Oxycoccus 

 palustris. 



Valerian. — See Valeriana. 



Valeriana. — Valerianece. — Pe- 

 rennial plants, mostly natives of Eu- 

 rope, which will grow in any com- 

 mon soil. The dwarf species are very 

 suitable for rockwork. 



Vallisne v ria. - -Hydrocharidece.-- 



"Water-plants, which succeed best in 

 a greenhouse, and which should be 

 planted in a layer of loam at the bot- 

 tom of the cistern in which they are 

 to be grown. The male and female 

 flowers are on different plants ; and 

 the latter rise on long spiral stalks, 

 which gradually uncoil above the sur- 

 face of the water, while the latter 

 are produced at the bottom. Before, 

 however, the anthers burst to dis- 

 charge the pollen, the male flowers 

 detach themselves from their stalks 

 and rise up to the surface, on which 

 they float like little white bubbles. 

 After the pollen has been distributed 

 over the stigmas, the male flowers 

 wither, and the spiral stalks of the 

 females coil up again so as to draw 



