MISC. PUBLICATION 110, TJ. S. DEPT. OF AGRICULTUKE 



between the veins, or (2) in cacti, 

 the restricted circular areas where 

 the spines and spicules are borne. 

 Aril: A fleshy growth from the apex 

 of a seed stalk or the placenta, 

 which envelops or becomes attached 

 to the seed. Familiar examples are 

 seen in species of waterlilies and in 

 bittersweet and its congeners 

 (Euonymus spp), 

 Aristate: Provided with an awn 



(Latin, arista) ; awned. 

 Articulate (d): Jointed, having a node 



or joint (Latin, articulus). 

 Ascending: Upcurved ; growing or di- 

 rected obliquely upward. 

 Asexual: Without sexual conjugation; 

 a term used in reproduction ; thus 

 a grass which propagates by root- 

 stocks is said to exhibit asexual re- 

 production. 

 Aspect: The gross physical appear- 

 ance of a plant or other organism. 

 Assimilation: The complex process of 

 forming protoplasm in the plant. 

 Anabolism and metabolism convey 

 similar meanings, but anabolism re- 

 fers only to building-up processes in 

 the plant, whereas metabolism also 

 includes the catabolic, or disinte- 

 grating processes. 

 Association: A unit of vegetation; a 

 group of associated plants. There 

 is no one definition of the term as- 

 sociation that is entirely satisfac- 

 tory to all plant ecologists, but there 

 is fairly general unanimity of opin- 

 ion that the 

 term associa- 

 tion should be 

 confined to the 

 larger or more 

 fundamental 

 plant growth 

 groupings, as, 

 for example, 

 "the yellow pine 

 association of 

 the far West". 

 Assurgent: As- 

 cending, espe- 

 cially when ris- 

 ing by curving 

 obliquely u p - 

 wards. 

 Attenuate : Long 

 or slender ta- 

 pering ; becom- 

 ing slender or 

 very narrow. 

 Auricled: Having 

 auricles, or 

 small earlike appendages or lobes, 

 usually at the base. (Fig. 7.) 

 Auriculate: Same as auricled. 

 Awn: A bristlelike appendage, espe- 

 cially on the floral bracts of grasses 



Figure 7. — Auricu- 

 late leaf, as in 

 mountain m a g - 

 nolia (M. fra- 

 seri) ; the ear- 

 like lobes at the 

 base of the leaf 

 blade are the au- 

 ricles 



or on the achenes of composites ; the 

 " beards " of wheat, rye, etc., are 

 awns. (Fig. 8, a.) 



Awned: Provided "with awns; bearded. 



Axil: The upper angle formed between 

 a plant stem or other axis and any 

 leaf, branch, or organ arising from 

 it; the axil of a 

 leaf is the point 

 or angle on the up- 

 per side at the 

 base of the leaf- 

 stalk or of a ses- 

 sile blade. 



Axile: Belonging to 

 an axis, as an 

 axile (central) 

 placenta. 



Axillary: Of or per- 

 taining to an axil; 

 occurring in or 

 borne at an axil. 



Baccate: Berry- 

 like. 



Banner: Topmost 

 petal in the corol- 

 la of a member of 

 the pea family 

 (papilionaceous 

 flower) ; same as 

 standard and 

 vexillum. (Fig. 

 9, a.) 



Barb: A twin, 

 sharp, down- 

 wardly or back- 

 wardly project- 

 ing point termi- 

 nating a bristle 

 (fig. 10, A), as on 

 the fruits of krameria and of certain 

 borages and umbellifers. 



Barbate: Bearded. 



Barbed: Beset with barbs. 



Figure 8. — Floret 

 of a needle grass 

 (Stipa sp.) ; a, 

 Awn ; b, body of 

 fruit (caryopsis 

 permanently in- 

 vested by the in- 

 durated lemma) ; 

 c, callus. The 

 callus and base 

 of the awn are 

 plumose, i. e., 

 feathery 



Figure 9. — Flower of 

 peavine (Lathyrus 

 sp.) ; a, Banner 

 (known also as 

 standard and vexil- 

 lum) 



Barbellate: Minutely bearded with 

 short stiff hairs; also sometimes 

 used as a synonym of " barbed." 



Basifixed: Attached by the base. 



Bast: The strong woody fibers in the 

 bark of trees and other woody 



