Part 90 (1/2)

Heads 12--20-flowered, radiate; the rays about 5, fertile (white).

Involucre somewhat cylindrical or club-shaped; the scales closely imbricated in several rows, cartilaginous and whitish, appressed, with short and abrupt often spreading green tips. Receptacle alveolate-toothed. Achenes short, inversely pyramidal, very silky; pappus simple, of numerous capillary bristles.--Perennial tufted herbs (1--2 high), with sessile somewhat 3-nerved leaves, and small heads mostly in little cl.u.s.ters, disposed in a flat corymb. Disk-flowers pale yellow. (Name from s??????, _silky_, and ?a?p??, _fruit_.)

[*] _Pappus rusty; leaves sparingly serrate, veiny, rather thin._

1. S. conyzodes, Nees. Somewhat p.u.b.escent; leaves oblong-lanceolate or the lower spatulate, ciliate; heads rather loosely corymbed, obconical (4--6” long).--Dry ground; Maine to Ohio, and southward. July.

[*][*] _Pappus white; leaves entire, obscurely veined, firmer and smaller._

2 S. solidagineus, Nees. Smooth, slender; leaves linear, rigid, obtuse, with rough margins, tapering to the base; heads narrow (3” long), in close cl.u.s.ters, few-flowered.--Thickets, S. New Eng. to Tenn., and southward. July.

3. S. tortiflius, Nees. h.o.a.ry-p.u.b.escent; leaves obovate or oblong-spatulate, short (--1' long), vertical, both sides alike; heads rather loosely corymbed, obovoid (4--5” long).--Pine woods, Va. and southward. Aug.

25. aSTER, L. STARWORT. ASTER.

Heads many-flowered, radiate; the ray-flowers in a single series, fertile. Scales of the involucre more or less imbricated, usually with herbaceous or leaf-like tips. Receptacle flat, alveolate. Achenes more or less flattened; pappus simple, of capillary bristles (double in ---- 4 and 5).--Perennial herbs (annual only in ---- 7 and 8), with corymbed, panicled, or racemose heads; flowering in autumn. Rays white, purple, or blue; the disk yellow, often changing to purple. (Name ?st??, _a star_, from the radiate heads of flowers.)

Conspectus of Groups.

Annuals, with copious fine soft pappus 53, 54

Pappus double 46--48

Scales closely imbricated, not green-tipped, often scarious-edged 49--52

Scales closely imbricated, scarcely at all herbaceous; leaves cordate, serrate 2, 3

Scales nearly equal, rigid, more or less foliaceous; pappus-bristles rigid, some thickened at top 1

Scales with herbaceous tips or the outer wholly foliaceous.

ASTER proper.

Pappus rigid; stem-leaves sessile, none cordate or clasping; heads few, large 4--8

Leaves silvery-silky both sides, sessile, entire 14, 15

Lower leaves more or less cordate, petiolate 17--24

Leaves entire, lower not cordate, cauline sessile with cordate-clasping base 16

Involucre (and branchlets) viscid or glandular; leaves not cordate, mostly entire, the cauline all sessile or clasping 9--13

Lower leaves all acute at base; not glandular nor viscid nor silky-canescent.

Smooth and glabrous, usually glaucous; scales coriaceous at base; leaves firm, usually entire 25--30

h.o.a.ry-p.u.b.escent or hirsute; scales squarrose; stem-leaves small, linear, entire 31, 32

Scales closely imbricated, not coriaceous at base; branches divaricate; heads many, small 33--35

Remaining species; branches erect or ascending.