Propagated by suckers which are taken from the base of the plant after flowering, when they have attained a good size. The best method to adopt is as follows: Take the sucker in the hand and gently twist it off the stem; next, trim the base by the removal of a few of the lower leaves, and then insert each sucker separately in a small pot, in sharp soil. A bottom heat of about 80° will greatly facilitate new root growth; failing this, they will root freely in the temperature of a stove, if placed in a shaded position for two or three weeks, after which they will bear increased light and sunshine during the latter part of the day. =Bilberry.= See Vaccinium. =Bindweed.= See Convolvulus. =Biophytum.= _Geraniaceæ._ Propagated by seeds sown in spring on a hot-bed. =Biota.= See Thuya. =Biotia.= See Madia. =Bird of Paradise Flower.= See Strelitzia. =Bird's-tongue Flower.= See Strelitzia. =Birch.= See Betula. =Birthwort.= See Aristolochia. =Bitter Sweet.= See Celastrus and Solanum. =Bitter Vetch.= See Orobus. =Bivonæa.= _Cruciferæ._ Increased by seeds, which should be sown in spring where the plants are intended to remain. They should be thinned out to insure full growth. =Bixa= (Arnatto). _Bixineæ._ Propagated by seeds sown when ripe, in bottom heat, or by cuttings put in sand under a hand-glass, in heat; the latter is the better method. =Blackberry= (_Rubus villosus_ and vars.). _Rosaceæ._ New varieties are obtained from seeds, which may be sown as soon as they are cleaned from the ripe fruit, or which may be stratified until the next spring. If the soil is in prime condition, fall sowing is preferable.