Cystolith. Mineral concretions, usually a calcium carbonate on a cellulose stalk, 

 occurring in special cells in the Urticaceae, etc. 



Deciduous. Losing leaves seasonally. 



Decompound. Said of compound leaves having divisions that are again dissected 

 (fig. 787). 



Decumbent. Reclining on the ground, with ascending apex (fig. 108). 



Decurrent. Extending down the stem below the insertion; said of leaves or ligules. 



Decussate. With successive pairs of organs arranged at right angles to one an- 

 other, causing them to appear 4-ranked. 



Deflexed. Turned back from point of attachment. 



Dehiscent. Opening and shedding contents; said of fruits and stamens (fig. 789). 



Deltoid. Triangular (fig. 787). 



Dendritic hairs. Hairs that branch like a tree (fig. 786). 



Dentate. Having marginal teeth pointing outward and not forward. Compare Ser- 

 rate. 



Denticulate. Bearing minute teeth directed outward. 



Depauperate. Much reduced and imperfect in structure and development. 



Determinate. Said of an inflorescence (as a cyme) in which the terminal flower 

 blooms slightly in advance of its nearest associates; limited in number and ex- 

 tent. 



Di-. Dis-. Greek prefix meaning two or double. 



Diadelphous. Stamens united by their filaments into two sets. 



Diaphragm. A dividing membrane or partition as that in the pith of grape vines 

 and the pith in Juglans. 



Dichotomous. Repeatedly forking in pairs. Dichotomy: a condition of being di- 

 chotomous. 



Dicotyledons (abbr. dicots). A class of angiosperms differentiated by possession 

 of two cotyledons. 



Didymous. Twin; found in pairs. 



Didynamous. With four stamens in two pairs of unequal length as in most Labiatae. 



Digitate. Fingered; shaped as an open hand; compound with the members arising 

 from one point. 



Dimorphic, dimorphous. Having two forms, as flowers with short stamens and 

 long styles or long stamens and short styles. 



Dioecious. Having staminate and pistillate flowers in different plants. 



Discoid. Disklike, in the Compositae, a head without ray florets. Disciform: flat 

 and circular like a disk. (fig. 741). 



Discrete. Separate, not coalescent. 



Disk, disc. A fleshy development of the receptacle about the base of the ovary; in 

 Compositae, the tubular flowers (disk florets) of the head as distinct from the 

 ray. 



Disparate. Unequal; dissimilar. 



Disposed. Referring to the ultimate arrangement, irrespective of point of origin; 

 thus, spirally arranged leaves may be disposed in two ranks so as to appear as 

 though coming from opposite sides of the stem. 



Dissected. Divided into several to many separate parts; said, for example, of the 

 bladeof aleaf (fig. 787). 



Dissepiment. A partition in an ovary or pericarp caused by the adhesion of the 

 sides of the carpellary leaves. 



Distal. Opposite the point of attachment; apical; away from the axis. 



Distichous. In two vertical rows or ranks. 



Divaricate, divaricately. Widely divergent. 



1712 



