454 



DAJfE S ROCKET 



DAME'S ROdXET and DAME'S VIOLET. Hesperis 

 miitirtiuili.s. 



DAMMAEA. See Agathis. 



DAMNACANTHUS {Greek, powerful spines). Biibi- 

 (ice(f. This iniiuotypic genus contains a tender, ever- 

 green, Japanese shrub, chiefly valued for its coral-red 

 berries, which remain on the bush until the fls. of the 

 next season are produced. Branches numerous, spiny: 

 Ivs. small, opposite, leathery, nearly sessile, broadly 

 ovate, acuminate ; fls. small, axillary, in I's or 2's, 

 white, fragrant; calyx tube obovoid, limb 4-5-cut; co- 

 rolla funnel-shaped. Prop, by cuttings. This plant may 

 be obtained from dealers in Japanese plants. 



Indicus, GiPrtn. (D. mdjor, Sieb. & Zucc). De.scribed 

 above. Himalayas and Jap. — Var. submitis is not so 

 spiny. 



DAMPING-OFF. A gardeners' phrase for a disas- 

 trous rotting of plants, especially of seedlings and cut- 

 tings, and generally at tin- surface of the ground. It is 

 usually associati'il witli ixccssive moisture in the soil 

 and air, with high and close temperatures, and some- 

 times poor light. Such conditions weaken the plants 

 and allow them to fall a prey to the minute parasitic 

 fungi which live upon the decaying vegetable matter in 

 the soil, and can remain alive for months, even if the 

 soil is thoroughly dry or frozen. As soon as the disease 

 is noticed, the healthy plants should be removed to 

 fresh soil, as the disease spreads rapidly. A whole 

 bench of cuttings may be ruined in a night. The skill- 

 ful propagator takes every possible precaution. His 

 benches have perfect drainage, he uses fresh sharp 

 sand, and sometimes sterilizes it with steam heat for 

 several hours. Damping-off is one of the most trying 

 experiences of the beginner, and nothing can prevent it 



673. Dalibarda repens. 



With perfect and cleistogamoiis flowers. 



but a thorough grasp of the principles of Greenhouse 

 Management in general, and Watering in particular. 

 (Consult articles on these subjects.) The terms Damp- 



DANDELION 



ing-off and Burning are also used for ruined flowers. 

 Burning is often caused by sunlight or by imperfections 

 in glass, but a flower spoiled by dripping cold water, or 

 by some unknown cause, is said to have a burned look. 



One of the commonest occasions of Damping-off is the 

 sudden flooding of a bed or bench after leaving it too 

 dry for a long time. 



674. Floret of D 

 enlarged. 



DAMSON. See Plum. 



DANiEA (a personal name). JUaratti<trew. A small 

 genus of fern-like plants, with synangia sessile, ar- 

 ranged in rows, and covering the entire under surface 

 of the leaf. They are rarely seen in cultivation in Amer. 



DANDELION (i. e., dent de Hon, French for (ion's 

 tooth: referring to the teeth on the Ivs.). The vernacu- 

 lar of Ttiriixacum officinAle, Weber, a stemless peren- 

 nial or biennial plant of the Oonipdsitce. It is native to 

 Europe and Asia, but is naturalized in all temperate 

 countries. On the Rocky Mts. and in the high north 

 are forms which are apparently indigenous. A floret from 

 the head of a Dandelion is shown in Fig. 674. The ovary 

 is at e; pappus (answering to calyx) at a ; ray of corolla 

 at c; ring of anthers at h; styles at d. The constricted 

 part at e elongates in fruit, raising the pappus on a long 

 stalk, as shown in Fig. 67.T ; and thus is the balloon of the 

 Dandelion formed. A Dandelion plant, with its scattering 

 fruits, is shown in Fig. G76. There is another species of 

 Dandelion in this country, but evidently not common. 

 It is the Red-seeded Dandelion {T. erythrospirmum, 

 Andrz.), with red seeds, not reflexed involucral scales, 

 and shorter beak. 



The Dandelion is much prized for "greens." For this 

 purpose it is cultivated in parts of Europe ; also about 

 Boston and in a few other localities in this country. 

 There are several improved large-leaved varieties, 

 mostly of French origin. Some of these named forms 

 have beautiful curled Ivs. Seeds are sown in the spring, 

 and the crop is gathered the same fall or the following 

 spring, —usually in the spring in this country. Com- 

 monly the seeds are sown where the plants are to stand, 

 although the jilaiitlets maybe transplanted. The plants 

 should stand alieut 1 foot apart each way, and a good 

 eroj. will citver the land completely when a year old. 

 Saudy or light loamy soil is preferred. The crop is har- 

 vested and marketed like spinach. The Ivs. or heads 

 are often blanched by tying them up, covering with 

 sand or a flower-pot. The plants are sometimes grown 

 more closely in beds, and frames are put over them to 

 force them. Roots are sometimes removed from the 

 field to the hotbed or house" for forcing. When treated 

 like chicory (which see), the roots will produce a win- 



