FLORA OF THE DISTRICT OF COLUMBIA. 295 



GLOSSARY. 



Abortive. Imperfectly developed; defective. 



Acaulescent. Stemless, or with the stem subterranean. 



Achene. A small dry one-seeded one-celled indehiscent fruit. 



Acuminate. Tapering at the end; long-acute. 



Acute. Terminating sharply in an angle of less than 90 degrees. 



Adherent. Joined to some other organ but structurally distinct from it. 



Adnate. Attached by one side or by its surface to a different organ or part. 



Adventive. Imperfectly naturalized. 



Aerial. Referring to above-ground organs or parts, as contrasted with those below 



ground. 

 Aggregate. Said of "polymorphous " species or groups of individuals not well under- 

 stood and suspected of including several distinct species or subspecies. 

 Alternate. Not opposite; arising singly at different heights. 

 Ament. A catkin or spike with flexible axiB, usually scaly. 

 Anastomosing. Connecting by branches or cross veins, forming a network. 

 Annual. Maturing from seed germinated within the year; of one year's duration 



only. 

 Anther. The pollen-bearing part of the stamen. 

 Anthesis. The time of opening of a flower. 

 Antrorse. Directed upward. 

 Apetalous. Lacking petals. 



Appressed. Lying closely against another organ or part. 

 Approximate. Situated close together, but not united. 

 Arcuate. Bowlike; lightly curved. 

 Aristate. Awned or bristle-tipped. 

 Articulate. Jointed. 



Ascending. Directed obliquely upward, or curving upward. 

 Attenuate. Long-tapering, becoming slender or very narrow. 

 Auricled. Having earlike appendages or basal lobes. 



Awl-shaped. Attenuate from the base to a slender or rigid point; subulate. 

 Awn. A bristle-like organ or appendage; in grasses, the continuation of the nerves 



of the bracts of the spikelet, sometimes stout and variously twisted, rarely trifid. 

 Axil. The angle formed between the axis and any leaf, branch, or organ arising 



from it. 

 Axillary. Arising from an axil; borne at an axil. 

 Beaked. Ending in an elongate, comparatively stout tip. 

 Bearded. Bearing long hairs in tufts or over small areas; barbate. 

 Berry. A fruit with fleshy pericarp. 



Bidentate. Having two teeth; or, as to margins, doubly toothed. 

 Biennial. Maturing during the second year from seed. 

 Bifid. Cleft into two parts. 

 Bilabiate. Two-lipped. 

 Bilobate. Two-lobed. 

 Btpinnate. Twice pinnate, that is, the primary divisions of a pinnate organ again 



pinnate. 

 Bipinnatifid. Twice pinnatifid, that is, the primary divisions of a pinnatifid organ 



again pinnatifid. 

 Blade. The expanded part of a leaf, sepal, or petal. 



Bract. A more or less modified leaf subtending a flower, flower cluster, or sporangium . 

 Bracteate. Having bracts. 

 Bracteolate. Having bractlets. 



