USNEA. 



323 



VALLISXERIA. 



and it is propagated by cuttings 

 like the double-blossomed kind, as 

 it has never yet been knoAvn to 

 ripen seeds. All the other kinds 

 are propagated by seeds, which they 

 ripen in great abundance. 



Ul'mus. — Ulniacece. — The Elm. 

 — The Weeping Elm is a very orna- 

 mental tree for pleasure-grounds. 



Umbili'cds. — Crassulacece. — 

 The new name for some of the kinds 

 of Navelwort. — See Cotyle''don. 



Umbrella Tree. — Magnolia 

 tripetala. — See Magno^lia. 



Undergrowth. — As nothing can 

 look worse than naked ground under 

 trees and shrubs, it is useful to know 

 what plants will grow under the 

 shade of trees. The best mode of 

 concealing the ground is to cover it 

 ■with ivy or laurel pegged down. 

 Evergreen climbing roses may also 

 be pegged dowTi, or Azaleas and 

 Rhododendrons. These last plants 

 make beautiful undergrowth, as 

 may be seen at Bagshot Park, High 

 Clere, Claremont, and other places. 

 The Aucuba, nearly all the Maho- 

 nias, and the different kinds of 

 Periwinkle, are all plants well 

 adapted for undergrowth. 



Ure^do. — Cryptogamia. --Akind 

 of rust often found on the leaves of 

 rose trees and other plants. — See 

 Mildew. 



Urti'ca. — Urticacece. — The Net- 

 tle. — The Roman Nettle, U. pihdl- 

 fera, is sometimes gro'mi in gardens 

 as an ornamental annual, but the 

 sting is much worse than that of U. 

 diolca, the common Nettle. Some 

 of the exotic species are very hand- 

 some ; as, for example, U. reticu- 

 lata^ a native of Jamaica, which has 

 red and yellow flowers and deep 

 green leaves. All the Nettles thrive 

 most in a deep rich soil. 



U'sNEA. — Cryptogamia. — Akind 

 of lichen that hangs down like a 

 beard from the branches of old trees, 



particularly Oaks, and has a very 

 picturesque appearance. 



UvcLA^RiA. — Melanthacece. — 

 Perennial hardy plants with pale 

 yellow flowers, natives of North 

 America, which should be 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 compost to plant them in. 

 If the subsoil be not good, the pit 

 may be made a little deeper, and a 

 layer of stones and brickbats may 

 be put at the bottom. The plants 

 are propagated by suckers, which 

 they produce in great abundance. 



yACCI'NIUM.— ^r/cace«.— The 

 ^ Whortle Berry. — Dwarf shrubs, 

 with pretty drooping heath -like 

 flowers and rather showy friut ; 

 found wild generally on commons in 

 Europe and North America. V. 

 MyrtUlus, the common Bilberry, is 

 the commonest species in England, 

 and there is a variety with white 

 berries in Germany. The Cran- 

 berry, F. Oxy coccus Lin., is now 

 called Oxycoccus palustins. 



Valerian. — See Valeria^na. 



Valeria'na. Valerianece. 



Perennial plants, mostly natives^of 

 Eui'ope, which will grow in any 

 common soil. The dwarf species 

 are very suitable for rock-work, 



Vallisne'ria. — Hydrocharldece. 

 — Water plants, which succeed best 

 in a greenhouse, and which should 

 be planted in a layer of loam at the 

 bottom 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 im- 

 coil above the surface of the water, 

 while the former are produced at 

 the bottom. Before, however, the 

 anthers burst to discharge the pol- 

 len, the male flowers detach them- 



