31G PROPAGATION OF PLANTS. 



They should be taken off late in winter or early spring 1 and planted in 

 pure sand under glass, but they do not require a high temperature or a 

 very copious supply of water while the roots are being produced. A 

 temperature of sixty degrees will insure the production of roots, and 

 with l^ss danger of the cuttings damping off than if exposed to a higher 

 temperature. The cuttings should be from two to three inches long, 

 the base cut just below a joint, and the leaves from the lower part 

 removed, while those above are shortened to about one-half their orig- 

 inal length. Carnation cuttings will usually strike root very readily in 

 an ordinary greenhouse, without placing them in close frames or where 

 they will receive bottom heat. It is well to shade the cuttings, or pro- 

 tect them from the direct rays of the sun, for a few days after planting. 

 A few species of Cerastium (Mouse-ear Chickweed) are cultivated in 

 greenhouses, and others for edgings of beds in summer or as border 

 plants. The same may be said of Lychnis and Silenes, and all are readily 

 propagated by seeds, cuttings, or division of the roots. 



Clstacece (Cistus or Rock Rose Family). A small order of elegant 

 shrubs or sub-shrubs, with very showy flowers of various colors, from 

 pure white to purple and yellow. The best known genera are Cistus and 

 Ifelianttiemum. There are many species and varieties of Cist us in culti- 

 vation, some of them quite hardy in our Northern States ; others are 

 tender, requiring the temperature of a cool greenhouse in winter. The 

 flowers are very handsome, but seldom last more than one day ; conse- 

 quently are of little value for cutting or using in bouquets. The IMian- 

 tlicmums are very similar to the Rock Rose in general appearance, but 

 not usually of as strong and robust habit. Some of the species are 

 annuals, but there are many half shrubby perennials. Propagated by 

 seeds, division of the clumps, and by green cuttings planted under glass 

 and treated as usual with such cuttings. 



Commelinacesce (Spiderwort Family). A large and widely distrib- 

 uted family of herbaceous plants, mostly tropical. Only a few genera 

 in cultivation, and the two most deserving attention are Commdina and 

 Tradescantia. The latter is usually represented in gardens by the very 

 common Spiderwort (T. Virginica), and in greenhouses by several varie- 

 ties of the Striped-leaved Spiderwort ( T. zebrlnd). The Commelinas are 

 only occasionally cultivated ; a few species are grown in greenhouses 

 for bedding out in summer, and among these there arc several tuber- 

 ous-rooted kinds, which should be lifted in the fall and stored in a dry, 

 warm place until spring. All readily propagated by seeds and divisions, 

 and the trailing kinds by cuttings and layers. 



Compositte (Composite Family). This is the most extensive family 

 of the entire vegetable kingdom, containing between seven and eight 

 hundred genera, and fully ten thousand species. They are mostly 

 herbs, but a few being shrubs ; the flowers, collected in a head on a 

 common receptacle, usually surrounded by an involucre bract, as seen 

 in the common Sunflower, Artichoke and single Zinnia. The genera 



