1879.] THE GARDENER'S PRIMER. 257 



what more pure white flowers ; while in point of size of flower and 

 sturdy compactness of habit, it is decidedly inferior to G. plicatus. 



Leucojum vernum. — A very beautiful Snowdrop-like subject in all its 

 parts, but larger than any Snowdrop at present known. The flowers 

 are pure white, tipped with green : they open in March. The plant is 

 easily grown in almost any soil if the drainage is good. 



W. Sutherland. 



Craigleith Nursery, Edinburgh. 



THE GARDENER'S PRIMER. 



NO. III. 



A practical acquaintance with the roots of different trees and 

 shrubs will soon teach the gardener how to discriminate their dis- 

 tinctive characteristics of growth and smell, so as readily to distin- 

 guish the roots of the ubiquitous Birch, the Portugal Laurel, Laburnum, 

 Quince, Scotch Eir, &c, or the Vine, or the beautiful roots of the 

 seedling Asparagus, or the roots of the Tussilago Farfara (Coltsfoot), 

 or the Couch-grass, or the Bell Bine, or the root of the Raspberry. 

 Some plants, such as Dracaanas and tuberous-rooted Geraniums, can 

 be readily propagated by cuttings made of the roots. 



Some plants, such as Ivy, are furnished with what are called adven- 

 titious roots, but as they are on the stem they are not true roots ; 

 nevertheless such roots after they enter the soil perform the functions 

 of true roots. 



Some plant-growths are often called roots which are not so : they 

 are prostrate or underground stems, such as the root of the Iris, which 

 is supplied on its under surface with rootlets, on its upper surface 

 with leaves, and is properly called a rhizome. The root of the Potato 

 is an axillary bud on an underground stem. The corm of the Cycla- 

 men, as it is sometimes called, is in reality an abrupt rhizome or 

 root-stock, analogous to that of the Primulaceae, to which family it 

 belongs. 



Bulbs are regarded as undeveloped stems or underground leaf- 

 buds, from which true roots will grow, but never a tap-root. They are 

 formed from seed, or from the axillary buds on the stem of the 

 bulb, and when perfected are of annual duration only : the same Tulip 

 does not blossom the second time. There are tunicated bulbs, as 

 Hyacinthus orientalis ; scaly bulbs, as Lilium candidum ; and these 

 scales, on removal from the bulb, may be propagated, and will form 

 bulbs. Some plants of the Aracese family will produce tuber-buds 

 above ground ; other tuberous-rooted plants, such as Gesneraceaa, 

 will produce, from the leaf, roots which soon develop tubers like the 



