Part 60

=B. polygalæfolia= (Polygala-leaved). _fl._ red; peduncles axillary, solitary, one-flowered. March to July. _l._ linear-lanceolate, quite entire, opposite, alternate, and three in a whorl. _h._ 1ft. to 3ft. Port Jackson, 1824.

=B. serrulata= (serrulate).* _fl._ of a deep rose colour, very fragrant; peduncles aggregate, terminal. July. _l._ trapeziform, acute, serrulated in front, smooth, full of glandular dots. _h._ 1ft. to 6ft. Port Jackson, 1816. (B. R. 842.)

=B. tetrandra= (four-stamened). _fl._ pale purple; pedicels short, one-flowered. May. _l._ impari-pinnate; leaflets four to five pairs, linear, obtuse, smooth; branches pilose. _h._ 1ft. to 4ft. New Holland, 1824. (P. M. B. 16, 227.)

=BORRERIA= (named after William Borrer, F.L.S., a profound botanist and cryptogamist). ORD. _Rubiaceæ_. A large genus of stove herbs or sub-shrubs, now referred to _Spermacoce_. Flowers small, white, rarely blue, disposed in verticillate heads, in the axils of the leaves, or on the tops of the branches, rarely cymose or corymbose. Leaves opposite, or the young ones disposed in fascicles in the axils of the old ones, and therefore appearing verticillate; stipules joining with the petioles, more or less sheathing, fringed by many bristles. Stems and branches usually tetragonal. The species are of easy culture, thriving in a light soil. Cuttings of the perennial kinds strike root readily in the same kind of soil, in heat. The annual kinds require a similar treatment to other tender annuals.

=B. stricta= (straight). A dwarf shrub, but closely allied to the next species. Porto Rico.

=B. verticillata= (whorled-flowered). _fl._ white. July. _l._ linear lanceolate, acuminated, opposite, but appearing verticillate from the fascicles of young leaves in the axils. _h._ 2ft. West Indies, 1732.

=BOSCIA= (named after Louis Bosc, a French professor of agriculture). SYN. _Podoria_. ORD. _Capparidaceæ_. A small genus of stove plants, requiring a soil of lumpy, fibry loam and peat. Propagated by cuttings of firm wood, placed in sand, under a glass, in heat.

=B. senegalensis= (Senegal). _fl._ white, small, apetalous, corymbose. _h._ 3ft. Senegal, 1824. An unarmed evergreen shrub. (L. E. M. 395.)

=BOSSIÆA= (named after M. Bossier Lamartinière, a French botanist, who accompanied the unfortunate La Peyrouse round the world). ORD. _Leguminosæ_. A genus of elegant Australian greenhouse shrubs. Flowers yellow, axillary and solitary, the base of the vexillum or the keel generally blotched or veined with purple. Leaves simple, of various forms. A mixture of turfy loam, leaf mould, peat, and sand, with very free drainage, suits these plants best. Half-ripened cuttings will root freely if placed in a pot of sand with a bell glass over them, in a cool house. Seeds should be sown, in March, on a slight hotbed.

=B. cinerea= (ashy-grey). _fl._ yellow, the vexillum furnished with a purple circle at the base, and the keel dark purple. May. _l._ nearly sessile, cordate acute, ending in a spiny mucrone, scabrous above, but pilose on the nerves beneath, with recurved margins. Branches terete, crowded with leaves, vinous. _h._ 1ft. to 3ft. 1824. SYNS. _B. cordifolia_, _B. tenuicaulis_. (B. M. 3895.)

=B. cordifolia= (heart-leaved). A synonym of _B. cinerea_.

=B. disticha= (two-ranked).* _fl._ yellowish-red; peduncles solitary, axillary, one-flowered, longer than the leaves. March to May. _l._ distichous, ovate, obtuse. Young branches terete. _h._ 1-1/2ft. Swan River, 1840. (B. R. 1841, 55.)

=B. ensata= (sword-shaped). _fl._ yellowish, with the back and base of the vexillum of a brownish orange-purple colour; keel brownish-purple. April. Branches flat, linear, leafless, toothed, the teeth bearing the flowers; upper bracts distant from the lower ones, shorter than the pedicel. _h._ 1ft. to 2ft. 1825. (S. F. A. 51.)

=B. foliosa= (leafy). _fl._ yellow and orange. May to June. _l._ alternate, small, orbicular, retuse, scabrous, with revolute margins, silky beneath; stipules permanent, hooked, longer than the petioles. Branches straight, terete, villous. _h._ 1ft. to 3ft. 1824.

=B. lenticularis= (lentil-leaved). A synonym of _B. rhombifolia_.

=B. linnæoides= (Linnæa-like).* _fl._ yellow; keel dark brown; corolla about twice the length of the calyx; pedicels solitary one-flowered, elongated. May. _l._ elliptic, mucronate. Branches terete, prostrate, puberulous. 1824. A procumbent shrub.

=B. linophylla= (Flax-leaved).* _fl._ orange and purple. July to August. _l._ linear, with recurved margins. Branches compressed, leafy. _h._ 1ft. to 4ft. 1803. (B. M. 2491.)

=B. microphylla= (small-leaved). _l._ cuneiformly obcordate, glabrous. Branches terete, leafy, spinescent; young branches rather compressed and pubescent. _h._ 1ft. to 2ft. 1803. (L. B. C. 656.)

=B. rhombifolia= (diamond-leaved).* _fl._ yellow, the vexillum having a dark red zonate mark at the base; wings red at the base; keel brownish-purple. April. _l._ rhomboidal-orbicular, somewhat emarginate and mucronate. Branches terete; branchlets compressed, leafy. _h._ 1ft. to 3ft. 1820. SYN. _B. lenticularis_. (L. B. C. 1238.)

=B. rotundifolia= (round-leaved). _l._ roundish, or broadly obovate, somewhat mucronate, flat, four to five lines long and five to six broad. Branches and branchlets leafy, compressed. _h._ 1ft. to 2ft. 1824.

=B. scolopendrium= (plank-plant). _fl._ yellow, with the back of the vexillum and keel brownish-red. May. _l._ (when present) ovate and smooth. Branches flat, linear, leafless, toothed, with the teeth bearing the flowers; keel naked; superior bracts permanent, imbricate, equal in length to the peduncles. _h._ 3ft. to 10ft. 1792. (B. M. 1235.)

=B. tenuicaulis= (slender-stemmed). Synonymous with _B. cinerea_.

=BOSWELLIA= (named after Dr. Boswell, formerly of Edinburgh). Olibanum Tree. ORD. _Burseraceæ_. Ornamental and economic evergreen stove trees. Flowers hermaphrodite; calyx five-toothed, permanent; petals five, obovate-oblong, spreading, with the margins incumbent in æstivation; disk cup-shaped, crenate; stamens ten; capsule trigonal. They are of easy culture, thriving well in loam and peat soil. Cuttings root readily if placed in sand under a glass.

=B. glabra= (glabrous). _fl._ white, small, with a red nectary and yellow anthers; racemes aggregate, simple, terminal, shorter than the leaves. _l._ impari-pinnate; leaflets broad, lanceolate, blunt, serrated, smooth. _h._ 30ft. Coromandel, 1823. (B. F. S. 124.)

=B. serrata= (saw-edged-leaved).* _fl._ whitish-yellow; racemes axillary, simple. _l._ impari-pinnate; leaflets ovate-oblong, taper-pointed, serrated, pubescent. _h._ 20ft. India, 1820. (T. L. S. xv., 4.)

=BOTANY BAY GUM.= _See_ =Xanthorrhæa arborea=.

=BOTANY BAY TEA= (and =TREE=). _See_ =Smilax glycyphylla=.

=BOTHY.= A residence for under-gardeners, usually built behind the hothouses, or some high wall, in what is called a back shed. The place is too frequently a cramped, ill-ventilated hovel. A Bothy proper should be an independent structure, and fitted with modern conveniences; for, of all people, gardeners are the most susceptible to colds, &c. A library of standard horticultural and botanical works, as well as a few on other scientific subjects, and a moderate number of high-class books of fiction, one or more weekly gardening and other papers, should be supplied by the employer. During the winter months, for mutual improvement, lectures should be delivered, or papers read, by each gardener, on various subjects, after which a free discussion should take place upon the paper or lecture, by which means a great amount of good would be accomplished.

=BOTRYCHIUM= (from _botrys_, a bunch; in reference to the bunch-like disposition of the indusia). Moonwort. ORD. _Filices_. A genus of very interesting and pretty little hardy ferns. Capsules sessile, arranged in two rows on the face of spikes which form a compound panicle. They require a compost of sandy loam; perfect drainage is most essential. For general culture, _see_ =Ferns=.

=B. australe= (southern). A variety of _B. ternatum_.

=B. daucifolium= (Daucus-leaved). _sti._ stout, 6in. to 12in. long; petiole of sterile segments 1in. to 6in. long, the latter 6in. to 12in. each way, deltoid, tripinnatifid or tripinnate, the lower pinnæ largest; segments lanceolate-oblong, 1/4in. to 3/8in. broad, finely toothed. _fertile peduncle_ equalling the sterile segments when mature; panicle 2in. to 4in. long; tripinnate, not very close. Himalayas, &c. Greenhouse species. SYN. _B. subcarnosum_.

=B. Lunaria.= Common Moonwort.* _sti._ 1in. to 4in. long. _sterile segments_ sessile, or nearly so, 1in. to 3in. long, 1/2in. to 1in. broad, base much broader than the middle, cut down to a flattened rachis into several distinct, close, entire, or notched cuneate-flabellate pinnæ on both sides. _fertile peduncle_ equalling or exceeding the sterile portion; panicle close, 1in. to 2in. long. England, &c. Hardy. See Fig. 267.

=B. lunarioides= (Lunaria-like). A variety of _B. ternatum_.

=B. obliquum= (oblique). A variety of _B. ternatum_.

=B. subcarnosum= (sub-fleshy). A synonym of _B. daucifolium_.

=B. ternatum= (ternate).* _sti._ 1in. to 2in. long. _petiole_ of the sterile segments 2in. to 4in. long, the latter 3in. to 6in. each way, deltoid, tri- or quadripinnatifid; lower pinnæ much the largest. _fertile peduncle_ 6in. to 9in. long; panicle 1in. to 6in. long; deltoid, very compound. Nootka and Hudson's Bay territory. Several so-called species come very close to this, including _australe_, _lunarioides_, and _obliquum_, which are only geographical varieties. Greenhouse species.

=B. virginianum= (Virginian).* _sti._ 3in. to 18in. long. _sterile segments_ sessile, 4in. to 12in. each way, deltoid, quadripinnatifid; lower pinnæ much the largest; pinnules oval-oblong, close, cut down to the rachis into finely cut linear-oblong segments. _fertile peduncle_ equalling or exceeding the sterile part of the plant when mature; panicle 1in. to 4in. long, loose, oblong. Oregon, and North United States, 1790. A hardy species in sheltered places. (H. G. F. 29.)

=BOTTLE-GOURD.= _See_ =Lagenaria=.

=BOTTLE-TREE.= _See_ =Sterculia rupestris=.

=BOTTOM HEAT.= This is usually secured by passing hot-water pipes through an air chamber, or a water tank, beneath a bed of plunging material. The covering of the tank or chamber is best made of slate. The heat must be regulated according to the requirements of the subjects grown; this is easily accomplished by using the valve. A thermometer should be placed in the tank or bed. Bottom-heat is indispensable for propagating plants from seeds and cuttings, especially in spring. _See_ =Heating= and =Hotbeds=.

=BOUCEROSIA= (from _boukeros_, furnished with buffaloes' horns; in reference to the curved lobes of the corona) ORD. _Asclepiadaceæ_. A genus of greenhouse succulent perennials, allied to _Stapelia_, and requiring the same culture. Flowers numerous, terminal, umbellate; corolla sub-campanulate, five-cleft; segments broadly triangular, with acute recesses; stramineous corona fifteen-lobed; lobes disposed in a double series; the five inner ones opposite the stamens and lying upon the anthers; the rest exterior, erect, or a little incurved at apex, adhering to the back of the inner ones. Branches and stems tetragonal, with toothed angles.

=B. europæa= (European). _fl._ purple-brown, yellow. Summer. _h._ 4in. Sicily, 1833. SYNS. _Apteranthes_ and _Stapelia Gussoniana_. See Fig. 268. (B. R. 1731.)

=B. maroccana= (Morocco).* _fl._ dark red purple, with yellow concentric lines. Summer. _l._ minute, trowel-shaped, deflexed at tip of stem angles. _h._ 4in. Morocco, 1875. (B. M. 6137.)

=BOUCHEA= (named after C. and P. Bouche, German naturalists). ORD. _Verbenaceæ_. A small genus of stove or greenhouse evergreen herbs or sub-shrubs. Flowers sub-sessile, in spicate racemes, which are either terminal or in the forking of two branches; corolla funnel-shaped. Leaves opposite, toothed. They thrive in a well-drained compost of loam and sandy peat. Propagated by cuttings, placed in sand, under a glass, and in a gentle heat, during spring.

=B. cuneifolia= (wedge-shaped-leaved). _fl._ white. April. _h._ 4ft. Cape of Good Hope, 1821. A greenhouse evergreen shrub. SYN. _Chascanum cuneifolium_.

=B. pseudogervao= (false-gervaô). _fl._ purplish, with white throat; spike terminal, 6in. to 10in. long, slender. September. _l._ opposite, ovate, or elliptic-ovate, acuminate, serrated. Stems tetragonous. _h._ 2ft. to 5ft. Brazil, 1874. A stove perennial. (B. M. 6221).

=BOUGAINVILLEA= (named after De Bougainville, a French navigator). ORD. _Nyctagineæ_. Gorgeous warm greenhouse or conservatory plants, comprising some of the most showy climbers in cultivation. Their beauty lies in the bracts, which envelop the small greenish flowers. _B. glabra_ may be grown in pots, or planted out in the greenhouse borders; the others are best planted out, as they root very freely, and plenty of space would be occupied if allowed, but it is best to limit it, as they bloom much better. Strict training and pinching are not desirable, being prejudicial to the free production of bloom; indeed, the best plan is to allow the plants to ramble freely over the roof of a moderately high house, or along the upper portion of a back wall; they will then bloom profusely for several months in the year, provided proper attention be paid to watering, and that the plants are in a well-drained situation. In preparing a border for their reception, the first point to be considered is the drainage, which must be perfect. This is best effected by placing a layer of brick rubbish, 6in. to 9in. in thickness, communicating with the drain, by which means all sourness and stagnancy of the soil will be obviated. The bed should be excavated to a depth of 18in. or 2ft. Three parts turfy loam, and one part leaf soil, with the admixture of a liberal quantity of sharp gritty sand, will form a suitable compost for the culture of Bougainvilleas. The amount of sand incorporated must depend upon the quality of the other components, heavy loam requiring more than that which is more friable. The occasional incorporation of manure in the compost is not to be recommended; but a liberal application of liquid manure will be of material advantage, especially if the root space is limited. When the plants cease blooming each year—-about November or December—-they should be dried off and rested; and in February they should be closely spurred in, the same as with vines, and all weak leaders removed, so that strong wood only is left. When grown in pots, they must be started in brisk heat. They are easily increased by cuttings prepared from the half-ripened wood; these should be placed in sandy soil, in a brisk bottom heat, when they will soon root. Scale, red spider, and mealy bug are the only insects likely to infest the plants, and recipes for their destruction will be found under each individual name.

=B. glabra= (smooth).* _fl._, inflorescence panicled, smaller than that of _B. speciosa_, each branchlet producing cordate-ovate acute rosy bracts, in threes. Summer. _l._ bright green, smooth. Brazil, 1861. This is by far the best species for pot culture, and forms a very showy plant when well grown.

=B. speciosa= (beautiful).* _fl._, bracts large, cordate, delicate lilac rose, produced in immense panicles, which, in well grown specimens, are so freely produced as to entirely shroud the whole plant. March to June. _l._ ovate, very dark green, covered on the upper surface with small hairs. Stems branched, abundantly furnished with large recurved spines. Brazil, 1861. (F. M. i., 62.)

=B. spectabilis= (showy). _fl._, bracts of a dull brick-red, shaded with scarlet. South America, 1829. It is very difficult to obtain bloom on this plant; and when flowers are produced, they are extremely ephemeral. The species is, for all practical purposes, much inferior to either of the foregoing. SYN. _Josepha augusta_. See Fig. 269.

=BOURBON PALM.= _See_ =Latania=.

=BOUSSINGAULTIA= (named after Boussingault, a celebrated chemist). ORD. _Chenopodiaceæ_. Very pretty half-hardy, tuberous-rooted plants, requiring a rich vegetable sandy soil, and a well-drained sunny aspect, under which conditions the first-mentioned species develops into a very luxuriant trailing plant, attaining a length of 20in. or more. Propagated freely by means of the tubercles of the stem; these are, however, extremely brittle.

=B. baselloides= (Basella-like).* _fl._ white, ultimately becoming black, fragrant, small, disposed in clusters, 2in. to 4in. long, which are axillary at the ends of the branches. Late autumn. _l._ alternate, cordate, smooth, shining, fleshy, slightly wavy. Stems very twining, tinged red, very quick-growing, producing tubercles. South America, 1835. (B. M. 3620.)

=B. Lachaumei= (Lachaume's). _fl._ rose, constantly in perfection. Cuba, 1872. A stove species.

=BOUVARDIA= (named after Dr. Charles Bouvard, formerly superintendent of the Jardin du Roi, at Paris). ORD. _Rubiaceæ_. Handsome greenhouse evergreen shrubs. Peduncles terminal, three-flowered, or trichotomous and corymbose; corolla funnel-shaped, tubular, elongated, beset with velvety papillæ outside, and a four-parted, spreading, short limb. Leaves opposite, or in whorls; stipules narrow, acute, adnate to the petioles on both sides. These extensively cultivated plants are among the most useful for conservatory or greenhouse decoration (see Fig. 270. for which we are indebted to Messrs. Cannell and Sons), and the flowers are largely employed in a cut state. Perhaps only two are fragrant, viz., _jasminiflora_ and _Humboldtii_. Cultivation: Presuming the grower to be commencing with young rooted cuttings, these should be potted off into a mixture of good fibrous loam, leaf soil, and sand, in equal proportions, to which may be added a small quantity of peat; they should then be placed in a temperature of from 70deg. to 80deg. until fully established in the small pots. It is necessary at this stage to stop the young plants back to the first joint, and as they continue to make fresh breaks, to keep on pinching them back during the whole period of cultivation, or until sufficiently bushy plants are produced. Many growers neglect stopping far too much, the result being ill-shaped and almost flowerless plants. The pinching, of course, can be regulated by the time the plants are required to flower; and it is unwise, in most cases, to stop them after the end of August. When the small pots are well filled with roots, the plants should be shifted into the flowering pots, viz., large 48-sized, which are quite commodious enough to grow very fine plants, a similar compost as in the first potting, with a little Standen's manure added, being used, and good drainage provided. A cool greenhouse, with a damp bottom for the pots to rest upon, and with a moist atmosphere, is the most suitable place in which to grow them during late spring and early summer, the moist air being very desirable as an effectual check to red spider, a pest very fond of the foliage, which it permanently disfigures. A cold pit or close frame is better during the summer months, as a moist atmosphere and cool bottom are then certain. Ventilation may be effected during the greater part of the day by tilting the lights below, and on fine nights they may be removed altogether. During bright sunshine, shading will be beneficial. All through the period of active growth, it is absolutely necessary that the plants should receive plenty of water, or they will surely suffer; and when the pots are filled with roots, occasional doses of manure water will be beneficial. Many cultivators plant them out about the end of June, in favoured situations, or in spent hotbeds, when they make very vigorous growth; and, if carefully pinched and watered, fine specimens are obtained. These are lifted in early autumn, with a good ball, potted, and kept shaded for a few days until the roots are again active, when they are taken to the house in which they are intended to bloom, and an enormous supply of flowers is secured. We have also seen Bouvardias planted out permanently in beds, in prepared pits, in which the winter temperature was not less than 55deg., with very satisfactory results; the quantity of bloom being very great. Of course, with the last-named treatment, it is essential to give the plants a rest and hardening-off after flowering, and when they are started into fresh growth to keep them well pinched and watered. Bouvardias are liable to the attacks of red spider and green fly. The former stands little chance of existence if the plants are kept well supplied with moisture; the latter may be destroyed by fumigating with tobacco. Mealy bug are also troublesome, and should be sponged off with a solution of Gishurst's Compound. Propagation: After flowering, and a slight rest and hardening-off, the old plants should be cut back, placed in heat, in a stove or cucumber pit, and freely syringed, which will cause them to break freely, and produce a good supply of cuttings. When the young shoots are from 1-1/2in. to 2in. long., they are in the best condition for striking. It is not necessary that they should be cut off at a joint, as they will root from any surface of the stem; and, working economically, it is wiser to cut them off just above the first joint, as other shoots will speedily break out, which may, in their turn, be taken. Pots about 5in. across should have previously been prepared for the cuttings, by being well drained and filled with a mixture of good fibrous loam, leaf soil, and coarse sand, in equal parts, with a copious supply of sand upon the surface, into which the cuttings should be dibbled pretty thickly. A good watering must be given without wetting, and thereby injuring, the foliage. The pots should be plunged in the cutting case, or in any bottom heat of about 70deg. or 80deg., and covered with a bell glass. All that is then necessary is to keep them moist and shady during sunshine, until they are rooted, which, as a rule, is effected in three weeks' time. When well established, they may be removed from the case, gradually hardened off, and finally potted singly into small thumb pots.

=B. angustifolia= (narrow-leaved).* _fl._ pale red; corymbs somewhat trichotomous. September. _l._ three in a whorl, lanceolate, with revolute edges, glabrous above, but beset with fine hairs beneath. Branches terete, smoothish. _h._ 2ft. Mexico, 1838. (P. M. B. 7, 99.)

=B. Cavanillesii= (Cavanilles's). _fl._ red; peduncles terminal, trifid, three-flowered. May. _l._ opposite, ovate-lanceolate, acuminated, rather villous beneath. _h._ 1-1/2ft. Mexico, 1846. SYN. _B. multiflora_. (J. H. S. 3, 246.)

=B. flava= (yellow).* _fl._ yellow, drooping; racemes three to five-flowered; pedicels downy, slender. March. _l._ opposite, ovate-lanceolate, ciliated; stipules setaceous. _h._ 1-1/2ft. Mexico, 1845. (B. R. 32, 32.)

=B. hirtella= (hairy). _fl._ pale red or flesh-coloured, corymbose. _l._ whorled, lanceolate, with revoluted edges, hairy on both surfaces. Branches terete. Mexico.