HENDERSON'S HANDBOOK OF PLANTS. 



closely together, as is done in forcing, in what is 

 known as a cold pit or sunken frame, which is 

 covered with leaves thick enough to keep out 

 the frost. By March 1st the leaves are all re- 

 moved except two or three inches, when sashes 

 are put on the frame or pit. By this forwarding 

 process Rhubarb may be had from three to four 

 weeks earlier than that grown out of doors. We 

 have in this article recommended raising Rhu- 

 barb from seed, as it is the cheapest and quick- 

 est way; and experience has shown us that the 

 varieties raised from seeds of either the "Vic- 

 toria" or " Linnseus" come true enough to the 

 originals for all practical purposes. Those, 

 however, who are particular to have these kinds 

 exactly correct, can obtain them by division. 



Rhexia. Deer Grass, Meadow Beauty. From 

 rhexis, a rupture; from its astringent qualities 

 it is supposed to cure ruptures. Linn. Octandria- 

 Mono<jynia. Nat. Ord. Mdastomacece. 



A small genus of very pretty hardy herbace- 

 ous perennials, common in sandy swamps from 

 New York west and south. The flowers are 

 bright pink, large and showy. The plants do 

 not grow above six or eight inches, but, from 

 their branching habit, completely cover the 

 ground with foliage and flower. 



Rhinopetalum. From rhin, a nose, and petalon, a 

 petal; base of the upper sepal. Linn. Hexandria- 

 Monogynia. Nat. Ord. LttiacecK. 



K. Kardini, the only known species, is a small 

 bulbous plant from Che Ural Mountains, its 

 flowers are pale pink, spotted, somewhat resem- 

 bling the Fritillaria. It is inferior in beauty to 

 the majority of its allies. It grows freely if cul- 

 tivated in the same manner as the Lily. Propa- 

 gated by offsets. Introduced in 1834. 



Rhipsalis. Coral Cactus. From rhlps, a willow 

 branch; referring to the flexible branches. Linn. 

 Icosamlria-Monofjynia. Nat. Ord. Cadaceoe. 



Very curious succulent plants, which are na- 

 tives of South America and the West Indies. 

 As the Opuntias may be said to be all leaves, 

 and the different kinds of tree Cereus all stem, 

 so the Rhipsalis may be said to be all branches; 

 for the whole plant consists of a series of short, 

 round, articulated branches, spreading in all 

 directions. The flowers of this genus differ 

 from those of Cacti generally, in being small 

 and not very handsome. They are generally 

 pale yellow. They require the same soil and 

 treatment as other Cactaceous plants. Propa- 

 gated by cuttings. The species are all natives 

 of the West Indies and South America. Intro- 

 duced in 1818. 



Rhipidopteris. From rhipis, a fan, and pteris, a 

 fern; referring to the formation of the fronds. 

 Linn.Crypto<jamiu-FUices. Nat. Ord. Polijpodiacece. 

 A small genus of Ferns allied to Polybotrya, 

 but differing in habit. The species are curious 

 little creeping plants, with small fronds from 

 one to three inches high. They are confined to 

 the West Indies and South America. They are 

 grown in the hot-house. 



Rhizophora. Mangrove. From rhiza, a root, 

 and pfioreo, to bear; the branches send down 

 roots like the Banyan Tree. Linn. Dodecandria- 

 Monoyynia. Nat. Ord. Rhizophoracece. 



The only known species constituting this ge- 

 nus is a large tree inhabiting the muddy swamps 

 close to the sea-shore in tropical climates. Its 

 interesting character is thus described by Dr. 

 Hamilton : " In the economy of Nature the Man- 

 grove performs a most important part, wresting 

 annually fresh portions of the land from the do- 



RHO 



minion of the ocean, and adding them to the 

 domain of man. This is effected in a twofold 

 manner: by the progressive advance of their 

 roots, and by the aerial germination of their 

 seeds, which do not leave their lofty position 

 till they have assumed the form of actual trees, 

 and drop into the water with their roots ready 

 prepared to take possession of the mud, in ad- 

 vance of their parent stems. The progression 

 by means of the roots is effected by fresh roots, 

 which issue from the trunk at some distance 

 above the surface of the water, and arching 

 down, penetrate the mud, establishing them- 

 selves as the pioneers of fresh invasions of the 

 retiring element. In this manner the plants, 

 after their descent from the parent trees, con- 

 tinue during their early years to advance stead- 

 ily forward, till they have obtained a height of 

 about fifteen feet, and gained a position consid- 

 erably in advance of their parent trunks. After 

 this fewer additions are made to the roots, but 

 the head begins to expand in every direction, 

 spreading its branches on all sides. These 

 branches, in their turn, send down long, slender 

 roots, like those of the Banyan Tree, (Ficus In- 

 dica,) which, rapidly elongating, descend from 

 all heights, and, reaching the water, penetrate 

 the mud, becoming in time independent trees. 

 Thus a complicated labyrinth is at length 

 formed." The fruit of the species is edible, and 

 its fermented juice is made into a light wine. 

 In Borneo a coarse, bitter salt is extracted from 

 their aerial roots. 



Rhodanthe. From rhodon, a rose, and anlhos, a 

 flower; in allusion to the color of the flower- 

 heads. Linn. Syngenesia-jEqualis. Nat. Ord. As- 

 teracece. 



A very oeautiful genus of half-hardy annuals 

 found in Western Australia. R. Manglesii and 

 its varieties have white, rose, crimson, and pur- 

 ple flowers. These plants are admirably adapted 

 for the border in summer or the conservatory or 

 green-house in winter, as they come into flower 

 early, and continue for a long time. The flowers, 

 if gathered when young, and dried in the shade, 

 will retain their beauty during the winter, mak- 

 ing them valuable for bouquets of dried flowers. 

 For perfection of growth in the border, the seed 

 should be sown in March in the green-house or a 

 hot-bed, and carefully grown on in small pots 

 until all danger from frosts is past, when they 

 may be turned out into the open border. For 

 winter flowering the seed should be sown in 

 August or September. Introduced by Capt. 

 Mangles in 1832. 



Rhodea. See Rohdea. 



Rhodiola. From rhodon, a rose. Linn. Dicecia- 

 Tetrar/ynia. Nat. Ord. Crassulacece. 



A genus of succulent plants, separated from 

 Sedum on account of their bearing fertile and 

 barren flowers on distinct plants. See Sedum. 



Rhodochyton. A genus of Scrophnlariacea*, dif- 

 fering but little from Lophospermurn, the calyx 

 being less divided, and the corolla not so open. 

 See Lophospermum. 



Rhododendron. Rose Bay. From rhodon, a rose, 

 and dendron, a tree. Linn. Decandria-Monofjynia. 

 Nat. Ord. Ericacete. 



A genus of well-known evergreen shrubs and 

 low-growing trees, remarkable for their beauti- 

 ful flowers, and thick, luxuriant, glossy foliage. 

 The species are widely diffused^ being indige- 

 nous to the United States, Europe, Asia, and 

 the Indies. Some of the species are perfectly 

 hardy, and others require the protection of the 



