249a. Heads solitary at the end of minutely leafy branchlets; leaves linear =Aster, Aster dumosus.= 249b. Heads in flat-topped clusters; leaves lanceolate or broader --250. 249c. Heads in more or less one-sided racemes --251. 249d. Heads in panicles or irregular clusters --253. 250a. Leaves rigid, linear-lanceolate =Aster, Aster ptarmicoides.= 250b. Leaves not rigid, lanceolate =Aster, Aster umbellatus.= 251a. Leaves lanceolate, sharply serrate --252. 251b. Leaves linear or narrowly linear-lanceolate, only the larger ones with a few teeth near the middle =Aster, Aster vimineus.= 252a. Stem glabrous or somewhat pubescent =Aster, Aster lateriflorus.= 252b. Stem woolly with long hairs =Aster, Aster lateriflorus var. hirsuticaulis.= 253a. Bracts narrow, approximately equal in length =Aster, Aster longifolius.= 253b. Bracts of several lengths, the outer successively shorter --254. 254a. Heads 10-15 mm. wide, including the rays =Aster, Aster tradescanti.= 254b. Heads 15-25 mm. wide, including the rays --255. 255a. Bracts with conspicuous dilated or subrhombic tips =Aster, Aster salicifolius.= 255b. Bracts without conspicuous green tips --256. 256a. Rays purple or rose; bog plant with linear leaves =Aster, Aster junceus.= 256b. Rays white, or slightly tinged with blue; leaves oblong to narrowly lanceolate =Aster, Aster paniculatus.= GLOSSARY =Achene.= A small, dry, hard, seed-like fruit containing a single seed. =Acuminate.= Taper-pointed. =Acute.= Ending with an acute angle. =Alternate.= Located singly on the stem, with other leaves above or below. =Annual.= Living but a single season. =Anther.= The (usually) enlarged end of a stamen, bearing the pollen. =Ascending.= Rising or curving obliquely upward. =Auricle.= An ear-shape appendage at the base of a leaf or other organ. =Auricled, auriculate.= Furnished with auricles. =Awl-shape.= Tapering to a slender stiff point. =Awn.= An awl-shape or bristle-shape appendage. =Axil.= The point on a stem just above the base of a leaf or branch. =Axillary.= Arising from or produced in the axil. =Basal.= Arising from or produced at the base. =Beak.= Ending in a prominent slender point. =Bract.= A small leaf near the base of a flower or flower-stalk, or in a flower-cluster. =Bracteal.= An adjective derived from bract. =Bipinnate.= A leaf with a pinnately branched axis, bearing leaflets on the sides of the branches. =Calyx.= The outer portion of the flower, usually green in color. In some plants it is colored to resemble (or replace) the corolla, and in others may be minute or wanting.