An Encyclopedia of Horticulture. 



335 



BiTJSCUS (the old Latin name, used by Virgil and 

 Pliny). Butcher's Broom. Ord. LiliacecB. 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. C'ladodes leaf-like, alter- 

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

 pimgent-pointed, rigidly coriaceous. The species thrive 

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



Fig. 399. Floweking Branchlet and detachep Fri'it ok 



RUSCUS ACl'LEATUS. 



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

 or IV'ttiKrue. //. <int' ov two, bracteateand bracteolate. February 

 to April. /V. brigbt red, rarely yellow, .Un. in diameter, ctaihdea 

 Jin. to l^in. long, ovate, rigid, spinescent, twisted at tlie liase. 

 Stems lOiu. to 2ft. high, erect. Europe (Britain), North Africa, 

 &c. See Fig. 399. (Sy. En. B. Ibl6.) 



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

 dniijijna. 



R. Hypophyllum (leaf-under-Ieaf). nimble Tongue. /. five or 

 si.\ in an uniliel, disitoseil in the niiilille of the lower cladodes. 

 .May and .Tune. Jr. red, .^iu. to :;lii. thick, cladndpti oblong or 

 olilong-Ianeeolate, 3in. to Sin. long ; upper ones alternate ; lower 

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

 to lift. .Mediterranean region, 1640. (B. M. 2049.) 11. Hi/pordog- 

 tiunt is regarded, by Mr. Baker, as a form of this species. 



R. racemosus (raceme-flowered). Alexandrian Laurel. rf. 

 greeuish-yellow, hermaphrodite, produced at the ends of the 

 branches. May. fi: red, with a round, coriaceous, wiiite disk 

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

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

 1739. P^vergreen shrub. (W. D. B. 145.) Danae racemom is the 

 correct name of this plant. 



BUSK. See JuncuB. The name is also commonly 

 applied to nmny species of allied and other genera. 



BUSH FEBN. See Schizea. 



BUSH, PLOWEBING. See Butomus. 



BUSH LILY. See Sisyrinchium. 



BUSSELIA (named in honour of Alexander Russel, 

 M.l->., F.R.S., author of a "Natural History of Aleppo," 

 17.")(>). Ubd. Scropliularinew. 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, 

 five-fid limb ; stamens four ; cymes diehotomous, bractoate, 

 many-flowered or reduced to one. Leaves opposite or 

 whorled ; those on the brancblets (which are often nodding 



Rnsselia — 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. liorlbunda (Inuulle-flowered). A synonym of R. rotundifnlia. 



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

 corolla lin. long ; peduncles elongated. July. t. linear, lanceo- 

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

 like. Brandies twiggy, rush-like, pendulous at apex. /(. 3ft. to 

 4ft. Mexico, 1833. (B. 220 ; B. B. 1775.) 



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



R. rotundifolia(rmmd-leaved). /. like those of K. mrmcntosa ; 

 jieduneles uiiiiiy-tlowered. 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. A. 4ft. Mexico, 1824. Syn. R. fioribunda. 



R, sarmentosa (sarmentose).* Jl. falsely whorled or loosely 

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

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

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

 L v.ariable, sometimes opposite or in whorls of three or four 

 on the s<ame 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. SVNS. R. multl- 

 Jiiira (B. M. 1528), .ft. teruifolia. 



R. ternlfolla (teruitte-leaved). A syu(pnyni of R. sarmentosa. 



BUST. 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 Uredinew 

 (see Fuccinia), to the forms distinguished as Credo, 

 Cceoma. Trichohasis. .'Eeidiitin, and Lecyfhw, formerly con- 

 sidered true genera, but now regarded only as stages in 

 the development of Puceinia and of allied genera. The 

 conidia, or spori?s, 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. 

 Piiceinin includes a very large number of species, some 

 of which {e.g., P. fjvaminis and allies) are called Mildews 

 when occurring on Wheat and other cereals. The more 

 common name for the species of Fuccinia and of Phrarj- 

 midimn is Brands ; but, occasionally, they are styled 

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

 Fhraifmidinni and Fuccinia. 



White Rusts dift'er much from Veedinece. though by 

 some they are associated with them, from the fact that 

 they prodiice conidia, which break away from the myce- 

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

 some forms of Uredinew. 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 Cystojiuts, and are 

 nearly related to Feronospora (which .lee). There are 

 few species in the genus ; and only one, O. rcindidus, is 

 really hurtful in gardens in this country. It grows on 

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

 causing distortions of these organs, and especially of 

 the flowers, which become much swollen, and remain 

 sterile. It may bo 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 Peronosimra. 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- 



