AN ENCYCLOPEDIA OF HORTICULTURE. 



335 



RUSCUS (the old Latin name, used by Virgil and 

 Pliny). Butcher's Broom. OBD. Liliacece. A small 

 genus (two or three species) of hardy plants, with erect, 

 branched, slightly woody stems, natives of Europe and 

 the whole Mediterranean region, from Madeira to the 

 Caucasus. Flowers small, usually on the face of the 

 cladode ; pedicels short, articulated at the apex. Berries 

 globose, pulpy, indehiscent. Cladodes leaf-like, alter- 

 nate or scattered, ovate or ovate - lanceolate, acute or 

 pungent-pointed, rigidly coriaceous. The species thrive 

 in common soil, and may be propagated by root-suckers. 



FIG. 399. FLOWERING BRANCHLET AND DETACHED FRUIT OF 

 RUSCUS ACULEATUS. 



R. acnleatus (prickly). Common Butcher's Broom ; Pettigree 

 or PetMgrue. rt. one or two, bracteateand bracteolate. February 

 to April, fr. bright red, rarely yellow, in. in diameter, cladodea 

 iin. to Uin. long, ovate, rigid, spinescent, twisted at the base. 

 Stems 10'in. to 2ft. high, erect Kurope (Britain), North Africa 

 &c. See Fig. 399. (Sy. En. B. 1516.) 



R. androgynus (hermaphrodite). A synonym of Semele an- 

 drogyna. 



R. Hypophyllum (leaf-under-leaf)-* Double Tongue, fl. five or 

 six in an umbel, disposed in the middle of the lower cladodes. 

 May and June. fr. red, iin. to Jin. thick, cladodes oblong or 

 oblong-lanceolate, Sin. to 5in. long ; upper ones alternate ; lower 

 ones opposite, ternate, or verticillate, distinctly costate. h. 1ft. 

 to lift. Mediterranean region, 1640. (B. M. 2049.) R. Hypoglos- 

 sum is regarded, by Mr. Baker, as a form of this speci 



R. racemosus (raceme-flowered). Alexandrian Laurel, fl. 

 greenish-yellow, hermaphrodite, produced at the end* of the 

 branches. May. fr. red, with a round, coriaceous, white disk 



. . . , , , 



at the base, cladodes oblong, acute, about 2in. long, rounded at 

 base, smooth, lucid-green, alternate, sessile. A. 4ft Portugal, 

 1739. Evergreen shrub. (W. D. B. 145.) Danae racemosa is the 

 correct name of this plant 



RUSH. See Juncus. The name is also commonly 

 applied to many species of allied and other genera. 



RUSH FERN. See Schizrea. 



RUSH, FLOWERING. See Butomus. 



RUSH LILY. See Sisyrinchium. 



RUSSELIA (named in honour of Alexander Russel, 

 M.D., F.R.S., author of a "Natural History of Aleppo," 

 1756). ORD. Scrophularinece. A genus comprising four 

 or five species of showy-flowered, stove, evergreen shrubs, 

 natives of Mexico and Central America. Calyx deeply 

 five-fid or five-parted, with closely imbricated segments ; 

 corolla scarlet, with a cylindrical tube and a sub-bilabiate, 

 nve-fid limb ; stamens four ; cymes dichotomons, bracteate, 

 many-flowered or reduced to one. Leaves opposite or 

 wfioriud ; those on the branchleta (which are often nodding 



Russelia continued. 



or pendulous) frequently reduced to small scales. All 

 the species introduced are described below. They thrive 

 in light, rich soil. Propagation may be readily effected 

 by cuttings, inserted in similar soil, under a glass, in 

 heat. 



R. floribunda (bundle-flowered). A synonym of R. rotundifolia. 

 R. juncea (Rush-like).* fl. in loose, remote-flowered racemes ; 

 corolla Iin. long ; peduncles elongated. July. I. linear, lanceo- 

 late, or ovate, small ; those on the branchlets minute and scale- 

 like. Branches twiggy, rush-like, pendulous at apex. h. 3lt. to 

 4ft. Mexico, 1833. (B. 220 ; B. R. 1773.) 



R. multiflora (many-flowered). A synonym of R. sarmentosa. 

 R. rotundifolia (round-leaved), fl. like those of A', sarmentosa ; 

 peduncles many-flowered. June. L sessile, orbicular, deeply 

 cordate at base, the cauline ones 2in. to 4in. long and broad, 

 reticulate-veined beneath, softly pubescent, closely sessile or semi, 

 amplexicaul. h. 4ft. Mexico, 1824. SYN. R. floribunda. 

 R. sarmentosa (sarmentose).* fl. falsely whorled or loosely 

 cymose : corolla more or less bearded on the throat below the 

 lower lip ; peduncles from three or four to thirty or forty- 

 flowered, axillary and remote, or in crowded racemes. July. 

 I. variable, sometimes opposite or in whorls of three or four 

 on the same specimen, cuneate or sub-cordate at base, acu- 

 minate and acute or obtuse, serrate or crenate, glabrous or 

 slightly hairy, h. 4ft. Central America, 1812. SYNS. R. muUi- 

 jlora (B. M. 1528), R. ternifolia. 

 R. ternifolia (ternate-leaved). A synonym of R. sannentona. 



RUST. Under this popular name, Fungi of more than 

 one group are included. The true Rusts, from which 

 the name has been derived, belong to the Uredinece 

 (see Puccinia), to the forms distinguished as I/redo, 

 Cceoma, Trichobasis, JEcidium, and Lecythce, formerly con- 

 sidered true genera, but now regarded only as stages in 

 the development of Puccinia and of allied genera. The 

 conidia, or sporps, in these forms are small, round or oval 

 cells, thrown off from the ends of the threads of myce- 

 lium, either singly or in rows. They fall off readily, 

 and the surfaces of the diseased plants, and of any body 

 that is rubbed on them, becomes covered with the spores, 

 like iron rust in colour and general appearance. They 

 are, accordingly, known as True Rusts or as Red Rusts. 

 Puccinia includes a very large number of species, some 

 of which (e.g., P. graminis and allies) are called Mildews 

 when occurring on Wheat and other cereals. The more 

 common name for the species of Puccinia and of Phrag- 

 midium is Brands ; but, occasionally, they are styled 

 Black Rusts. For an account of all these forms, see 

 Phrag-midium and Puccinia. 



White Rusts differ much from Uredinece, though by 

 some they are associated with them, from the fact that 

 they produce conidia, which break away from the myce- 

 lium, and which are grouped in patches, much as in 

 some forms of Uredinece. Like these also they cover 

 bodies rubbed against them with a powdery coating of 

 conidia ; but the latter are white, not rusty-red. The 

 White Rusts belong to the genus Cystopus, and are 

 nearly related to Peronospora (which see). There are 

 few species in the genus; and only one, C. candidus, is 

 really hurtful in gardens in this country. It grows on 

 the leaves, stems, and flowers of many of the Cruciferoe, 

 causing distortions of these organs, and especially of 

 the flowers, which become much swollen, and remain 

 sterile. It may be found on Cabbage, Turnip, Radish, 

 Horseradish, and many wild Cruciferce, e.g., Shepherd's 

 Purse and Watercress. It is common in North America 

 as well as in Europe. A microscopic examination of a 

 section through one of the white spots, which are plen- 

 tifully scattered over the diseased organs, shows a layer 

 of mycelium, from which rise branches, each of which 

 bears on its tip a beadlike row of conidia. These fall 

 off one after the other. When they fall into water, the 

 contents break up into five or six zoospores, like those 

 in Peronospora. These bodies escape by a hole, which 

 opens at one end of the conidium, and move about for 

 a time in the water by means of two hairs or cilia. 

 Afterwards, they settle down, and push out a mycelium- 



