Propagated by divisions of the roots, made in early spring or after flowering. Also by seeds. =Ceanothus.= _Rhamneæ._ Increased by layers, which is the readiest way of obtaining strong plants, or by cuttings, which should be inserted in a cold-frame. =Cecropia= (Snake Wood). _Urticaceæ._ Propagated by cuttings of ripened shoots. Place in sandy peat in a moist bottom heat. =Cedar.= See Cedrus. =Cedrela= (Bastard Cedar). _Miliaceæ._ Increased by large ripened cuttings, placed in sand, in heat. =Cedronella.= _Labiatæ._ The herbaceous species by division of the roots or by cuttings of young wood. _C. triphylla_ by cuttings. =Cedrus= (Cedar). _Coniferæ._ Increased by seeds, which are difficult to extract from the cones. Gather the cones in spring, and sow the seeds immediately in pans. Varieties are propagated by veneer grafts. =Celastrus= (Staff-tree, Bitter-sweet). _Celastrineæ._ Propagated by seeds and suckers, also by layering the hardy species in autumn. Ripened cuttings will root freely in a compost of loam, peat and sand. =Celery= (_Apium graveolens_). _Umbelliferæ._ By seeds, as described on page 12; or, for the early crop, sow under glass, as in a hot-bed. =Celosia= (Cockscomb). _Amarantaceæ._ Propagated by seed sown in spring, in pans of well-drained, rich, sandy soil or in the open. =Celsia.= _Scrophularineæ._ Increased by seeds, which may be sown in the open border and thinned out for flowering, or raised in nursery beds and transplanted. _C. Arcturus_ should be increased by cuttings, the young wood striking freely in a cool house or frame. =Celtis= (Nettle-tree). _Urticaceæ._ Increased by seeds, which should be sown as soon as ripe. By layers, and by cuttings of ripened shoots in autumn. =Centaurea.= _Compositæ._ Annuals by seeds, which may be sown in the open border. To propagate _C. Cineraria_, and some others sow seeds in August in slight heat, or make cuttings about the beginning of September. =Centranthus.= _Valerianeæ._ Increased by seeds sown in spring. =Centronia.= _Melastomaceæ._ Propagated by cuttings of half-ripened shoots, which should be inserted in peat and sand, under glass. =Centropogon.= _Campanulaceæ._ Increased by seeds, by divisions and by cuttings from any young shoots three or four inches long. Take off with a heel and place in sharp sandy soil, close around the edge of the pot, and then keep close under a propagating-box, in a temperature ranging between 60° and 70°. =Cephælis.= _Rubiaceæ._ Increased by cuttings of firm young shoots, which will root well in sandy soil under a hand-glass, in moist stove heat. =Cephalanthus= (Button-wood). _Rubiaceæ._ Seeds. Propagated by layers or ripened cuttings in autumn. =Cephalotus.= _Saxifrageæ._