HENDERSON'S HANDBOOK OF PLANTS. 



DIG 



Dichotomia, Dii'hrtomous. Having the divi- 

 sions always in pairs; a term equally 

 applied to branches, or veins, or forks. 



Ifalesium.A. one-seeded indehiscent fruit 

 inclosed within a hardened perianth, as 

 in the Marvel of Peru. 



DirliiinuH. Having the stamens in one 

 flower and the pistil in another. 



Dicotyledonous. Having two cotyledons. 



Dicotyledons, Dicotyledonece. Plants having 

 two seed leaves, which are called cotyle- 

 dons. This is one of the primary divi- 

 sions or classes of the vegetable king- 

 dom, including about 7,000 known gen- 

 era, and about 70,000 known species of 

 flowering plants. The class also receives 

 the name of Exogence or Exogens, from 

 the structure of the stems. The plants 

 of this great class have spiral vessels; 

 their stems are formed by additions ex- 

 ternally in the form of zones or rings; 

 stomata or pores exist in the leaves, which 

 have a reticulated or netted venation. 

 The plants have stamens and pistils, 

 either in the same or in different flowers. 

 The symmetry of the flowers is repre- 

 sented by five or two, or multiples of 

 these numbers. The ovules are contained 

 in an ovary, or more rarely are naked; 

 and the embryo has two, sometimes more, 

 cotyledons. 



Dictyogens, (Dictyogena?.} A sub-class of 

 Monocotyledons or Endogens, according 

 to Lindley. 



Didymouf,. Double; growing in pairs, as 

 the fruit of Umbellifers. 



Didynamia.An artificial class in the Lin- 

 nnean system, characterized by the flow- 

 ers being irregular, and containing four 

 stamens, of which two are longer than 

 the other two. 



Didynamous. Having two long stamens 

 and two short ones in the same flower. 



DIM 



Dijformis. Having an unusual shape, or 

 remarkable for some singularity of shape. 



Diffuse. Scattered, widely spread, as in 

 Veronica saxatilis. 



Digamous. When two kinds of flowers, 

 some male and others female, are placed 

 on the same receptacle in Composite. 



Digging. This is now nearly all done by 

 the digging fork in place of the spade, 

 unless in soils that are being broken up 

 from sod. The fork pulverizes the soil 

 much better, (the only object to be at- 

 tained by digging,) is much lighter to 

 handle, and the wonder is why, for gen- 

 erations, the spade was used, when the 

 manure fork, at the same time in use, 

 had not suggested its value for digging 

 purposes. 



Digilaliform. Like campanulate, but longer 

 and irregular, as the corolla of Digitalis. 



Digitate. Where several distinct leaflets 

 radiate from the point of a leaf-stalk; 

 applied to a simple leaf, where the lobes 

 are very narrow, deeply cut, and all ex- 

 tending nearly to the base of the limb, 

 like the extended fingers of the human 

 hand, as in the Horse-Chestnut, Lupins, 

 Spircea palmata, etc. 



Digitinerved. When the ribs of a leaf radi- 

 ate from the top of the petiole. 



Digitus, (adj. Digitalis.) The length of the 

 index finger ; about three inches in length. 



Digynia. An order, in some of the classes 

 of the artificial system of Linnseus, char- 

 acterized by the flowers having two pistils, 

 or at least two different styles. 



Digynous. Having two styles or female 

 organs. 



Dimidiate. When one half of an organ is 

 so much smaller than the other as to 

 seem as if missing; hardly different from 

 oblique, except in degree; also slit half 

 way up. 



