THE ORNAMENTAL PLANTS— BULBS 281 



June; flowers, small, white to purplish, very numerous and borne 

 in large panicles. 

 Trollius Europijeus. — Height, 1| to 2 feet; fourth week of May; 

 flowers, large, bright yellow, continuing a long time. 



4. Bulbs and Tubers 



(See the particular culture of the different kinds in Chapter 

 VIII ; and instructions for forcing on p. 345.) 



It is customary to write of bulbs and tubers together, be- 

 cause the tops and flowers of all the bulbous and tuberous 

 plants spring from large reservoirs of stored food, giving rise to 

 similar methods of culture and of storage. 



Structurally, the bulb is very different from the tuber, how- 

 ever. A bulb is practically a large dormant bud, the scales 

 representing the leaves, and the embryo stem lying in the center. 

 Bulbs are condensed plants in storage. The tuber, on the other 

 hand, is a solid body, with buds arising from.it. Some tubers 

 represent thickened stems, as the Irish potato, and some thick- 

 ened roots, as probably the sweet-potato, and some both stem 

 and root, as the turnip, parsnip, and beet. Some tubers are very 

 bulb-like in appearance, as the corms of crocus and gladiolus. 



Using the word ''bulb" in the gardener's sense to include 

 all these plants as a cultural group, we may throw them into 

 two classes: the hardy kinds, to be planted in fall; and the 

 tender kinds, to be planted in spring. 



Fall-planted bulbs. 



The fall-planted bulbs are of two groups: the "Holland 

 bulbs" or early spring bloomers, as crocus, tulip (Fig. 255), 

 hyacinth (Fig. 262), narcissus (Fig. 260), squill (Fig. 256), 

 snowdrop; the summer bloomers, as hlies (Figs. 258, 259). 

 The treatments of the two groups are so similar that they may 

 be discussed together. 



