249d. Heads in panicles or irregular cl.u.s.ters --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 p.u.b.escent =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.

=Ac.u.minate.= 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-cl.u.s.ter.

=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.

=Capitate.= Shaped like a head; or arranged in a dense compact cl.u.s.ter.

=Capsule.= A dry fruit with usually several seeds, opening at maturity.

=Catkin.= A cylindrical or ovoid cl.u.s.ter of inconspicuous flowers, for example, the "p.u.s.s.y willow."

=Cells of ovary.= The cavity or cavities within an ovary, in which the seeds are produced.

=Ciliate.= Provided with hairs at the margin.

=Clasping.= With the base of a leaf or other organ wholly or partly surrounding the stem.

=Cleft.= Deeply divided toward the base or the mid-rib.

=Closed sheath.= A leaf-sheath in which the margins are united to form a tube.

=Composite.= A flower-cl.u.s.ter containing several or many small flowers, closely crowded together and provided with calyx-like bracts, so that the whole cl.u.s.ter resembles a single flower.

=Compound.= Composed of 2 or more similar parts united, as a compound ovary.

=Compound leaf.= A leaf with two or more separate leaflets on a single petiole.

=Connate.= Grown together.

=Cordate.= Heart-shape. A whole leaf-blade may be cordate, or the term may be applied to the base of a leaf only.