AND GENEBAL HOBTICULTURE. 



133 



DBA 



nearly every joint. The most forward of these 

 may be removed from the stem from time to 

 time, which will soon strike root in sand with 

 bottom heat. The old stem should not be 

 removed until its reproductive powers are 

 exhausted. The species are pretty generally 

 distributed throughout all tropical and sub- 

 tropical countries, and were first brought to 

 notice about 1820. See Cordyline. 

 Dracoce'phalum. Dragon's Head. Prom dra- 

 kon, a dragon, and kephnle, a head ; referring 

 to the gaping flower. Nat. Ord. Labiaim. 



This genus consists of hardy annuals 

 and perennials, several of which are well 

 known as garden flowers, among which may 

 be found D. Moldavicum, the Moldavian Balm, 

 a hardy annual with blue flowers. Several 

 hardy species, perennials, natives of Siberia, 

 have beautiful large blue flowers. One very 

 pretty species, D. parviflorum, is sparingly 

 met in the Northern and Western States. All 

 are propagated by seed or by root division. 

 Introduced in 1731. 



Draco'ntium. A genus of Aroidem, natives of 

 tropical America, comprising certain species 

 more remarkable than beautiful or orna^ 

 mental ; useful only in large collections. 



Dracophy'llum. A genus of Epaeridacem, con- 

 sisting of about twenty-five species, natives of 

 New Zealand and Australia. D. capitaium, 

 with pure white flowers in terminal heads, 

 and D. gracile, also white, but more slender in 

 growth, are both very pretty plants when well 

 grown. 



Dragon-Arum. Arum Dracwnadus. 

 Green. Ariacema Draconlium. 



Dragon's Blood. This resin, used in medicine, 

 etc., is furnished by Calamus Draco, and is 

 imported from Sumatra, southern Borneo, 

 etc. The name Dragon's Blood is also given 

 to resins yielded by Draccena Draco in the 

 Canary Islands, and by Draeaana cinnaba/rma 

 in Socotra, and also by Plerocarpu^ Draco. 



Dragon's-Blood-Tree. Draccena Draco. 



Dragon's-head. The genus Dracocephalum. 



Dragon's-mouth. Antirrhiv/wm majus. 



Dragon-tree. Canary Islands. Draccena Draco. 



Draining. This is one of the most important 

 operations in horticulture. No matter how 

 fertile the normal condition of the soil; no 

 matter how abundantly it is fertilized; no 

 matter how carefully and thoroughly it Is 

 tilled, if water remains in it at the depth to 

 which roots penetrate, all labor will be in vain ; 

 for no satisfactory result can ever be attained 

 until the water is drained off. The subject is 

 one of such importance that we cannot give it 

 full attention here, and to such as require to 

 operate on a large scale, works specially 

 devoted to the subject should be consulted, or 

 a draining engineer employed. Soils having a 

 gravelly or sandy sub-soil ten or twenty 

 inches below the top soil do not usually need 

 draining ; but in all soils underlaid by clay or 

 hard pan, draining is indispensable, unless in 

 cases where there is a slope of two to three 

 feet in a hundred; and even in such cases 

 draining is beneficial if the sub-soil is clay. 



In soils having a clay or hard-pan sub-soil, 

 drains should be made three feet deep and 

 not more than twenty feet apart. If stones 

 are plenty, they may be profitably used to fill 



DEI 



up the drains, say to a depth of twelve or fif- 

 teen inches, either placed so as to form a 

 "rubble" drain, if the stones are round, or 

 built with an orifice at the bottom, if the 

 stones are flat. In either case, care must be 

 used to cover the stones carefully up with 

 inverted sods, or some mateiial that will pre- 

 vent the soil being washed through the stones 

 and choking up the drain. 



Drain tiles, when they can be obtained at a 

 reasonable price, are the best material for 

 draining. The horseshoe pattern is generally 

 used. If the drain has a hard bottom they 

 can be placed directly on it when leveled to 

 the proper grade; but if the ground is soft 

 and spongy, a board must be laid in the bot- 

 tom, on which to place the tiles. It is often a 

 very troublesome matter to get the few drain 

 tiles necessary to drain a small garden, and in 

 such cases an excellent and cheap substitute 

 can be had by using one of boards. Take 

 ordinary rough boards — ^Pine, Hemlock or 

 Spruce — and cut them into widths of three or 

 four inches, and nail them together so as to 

 form a triangular pipe, taking care to "break 

 the joints " in putting the lengths together. 

 Care must be taken that the boards are not 

 nailed together too closely, else they might 

 swell so as to prevent the water passing into 

 the drain to be carried off. These drains are 

 usually set with a flat side down, but they will 

 keep clear better if put with a point down, 

 though it is more trouble to lay them. Drains 

 made in this way wi}l last twenty years or 

 more. 



Of course, in draining, the greater the fall 

 that can be got the better, though, if the 

 grading is carefully done by a competent 

 engineer, a very slight fall will sufflce. Some 

 of the trunk or main sewers in our cities have 

 only a grade of one foot in a thousand. 



Drainage in flower pots is essent.al for most 

 plants whenever the pot is over five inches in 

 diameter. Charcoal broken into pieces from 

 one-half to one inch in diameter we prefer to 

 every other kind of drainage, which should 

 be in depth from one inch to three inches, ac- 

 cording to the size of the pot to be drained, 

 an extra quantity being necessary if the plant 

 is being shifted into a pot too, large ; then 

 ample drainage is indispensable to admit of 

 the quick escape of water. This drainage, so 

 called, is not alone of use as a means for the 

 rapid escape of water, but also for the admis- 

 sion of air to the roots, which brings in 

 another important matter in connection with 

 the drainage in pots, the necessity to stand 

 the pots on some rough material, such as 

 gravel or cinders ; for if placed on sand, soil, 

 or anything that will close up the orifice in 

 the bottom of the pot, all the drainage placed 

 in it will avail nothing. It is far better to use 

 no drainage at all, and stand the pots on a 

 rough surface, than to use the drainage and 

 place the plants on some material that will 

 close the outlet. 

 Dii'mia. Trom drimya, acrid ; referring to the 

 juice of the bulbs. Nat. Ord. lAUacem. 



A small genus of green-house bulbs from 

 the Cape of Good Hope. The flowers are 

 white, purple, red, green, and variegated, and 

 resemble the Ixias, though not as showy. 

 The juice of the bulb is very acrid, causing 

 blisters when applied to the skin. Propa- 

 gated by offsets. Introduced in 1800. 



