GLOSSARY. 



Abortive. Applied to organs that remain rudimentary, and do not attain 

 perfection in form or function. Commonly applied to anthers and 

 ovules (p. 391). 



Acaulescent. Stems so reduced as to make the plant seem stemless, as in 

 Aletris (p. 490). 



Accumbent. Cotyledons which are so folded that their edges are opposite 

 the hypocotyl, as in the seeds of the water cress and other Cruciferae. 



Achene (Achenium). A non-fleshy, or so-called dry, unilocular and one- 

 seeded, indehiscent fruit, in which the pericarp is more or less firm 

 and may or may not be united with the seed (p. 410). 



Achlamydeous. Flowers without a perianth. Applied to plants in which 

 the flowers have neither calyx nor corolla, as the Willows. 



Acute. Applied to a sharp pointed summit, the edges of which form an 

 angle which is less than a right angle. Specifically applied in describ- 

 ing the summits of leaves and leaf-like organs. 



Adhesion. Same as adnation. See adnate. 



Adnate. The congenital union of different organs. Applied to stamens 

 when the anther adheres longitudinally to the filament (p. 381) ; also 

 to the union of different circles in the flower, as of stamens with 

 corolla and the calyx tube with the ovary (p. 390). 



Adventive. Applied to introduced plants, which are only locally spon- 

 taneous and not thoroughly naturalized. 



Aestivation. See Estivation. 



Akene. See achene. 



Aleurone. Applied to complex plant proteins consisting of a phyto- 

 . globulin, one or more globoids and other substances (p. 193). 



Alkaloid. An organic base occurring in certain plants, usually in com- 

 bination with organic acids and exhibiting distinct chemical reactions 

 and having marked physiological properties. 



Alternate. Following each the other in spiral succession. Usually applied 

 to leaves (p. 363). 



Alternation of Generation. The alternation of two generations, as of 

 gametophyte and sporophyte in the Archegoniates (p. 75). 



Alveolate. Honeycomb like; having angular depressions (alveoli) sepa- 

 rated by thin walls. Applied to the receptacles of the flowers of the 

 Compositae. 



Ament (Amentum). A spike consisting of unisexual, apetalous flowers, 

 subtended by scales or bracts as the inflorescence in the Salicaceae 

 (p. 508). k 



Amphitropous (Half-anatropous). An ovule or seed having a partial 

 raphe so that the hilum is lateral and intermediate between the 

 chalaza and micropyle. 



Amplexicaul. Nearly surrounding or clasping the stem as the base of 

 some leaves. 



Anabolism. Constructive metabolism, as in photosynthesis, whereby com- 

 plex substances are built up from simpler ones (p. 252). 



Anastamosing. The branching and interlacing of the veins of leaves so 

 as to form a well defined network. 



Anatropous. A form of ovule that is inverted on its stalk, the latter 

 forming a lateral ridge or raphe extending the length of the seed and 

 connecting the hilum and the chalaza (p. 379). 



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