A. linearis (linear). fl. white; umbels dividing in threes, lateral and terminal. July. l. 1in. long, opposite, linear-lanceolate. Stem glabrous. Cape of Good Hope, 1816.
A. triflorus (three-flowered).* fl. white; umbels generally three-flowered. July. l. opposite, lanceolate, villous beneath. Stems hairy. Cape of Good Hope, 1816.
ASTER (from aster, a star; general shape of flower-heads). Michaelmas Daisy; Star-wort. SYN. Pinardia (of Necker). ORD. Compositæ. Hardy herbaceous perennials, except where otherwise stated. Heads solitary, corymbose, or panicled, heterogamous, rayed; ray florets pistiliferous, one or two-seriate, fertile or neuter; ligule elongated, white, blue, or purple; disk florets hermaphrodite, fertile, tubular, yellow, five-cleft; involucre campanulate or hemispheric; bracts few or many-seriate, outer smaller or larger; receptacle flat or convex; pappus hairs few or copious, scabrid, outer sometimes shorter, rigid, and paleaceous. Leaves alternate. This large genus contains many handsome border and alpine deciduous perennials (rarely biennials) of easy culture in ordinary soil. They may be propagated by divisions in autumn or spring, or by seeds in spring. The greenhouse species are mostly evergreen shrubs, requiring a compost of peat, leaf soil, and loam. Cuttings root readily in a sandy soil, under a hand glass, with very little heat.
A. acris (acrid). fl.-heads blue; involucre imbricated, twice as short as the disk. August. l. linear-lanceolate, not dotted, three-nerved. h. 2ft. South Europe, 1731.
A. acuminatus (taper-pointed).* fl.-heads white; panicle corymbose. September. l. broad-lanceolate, narrowed at base, entire, with a very long point. Stem simple, flexuous, angular. h. 2ft. North America, 1806.
A. adulterinus (false). fl.-heads violet; involucre squarrose, shorter than the disk. September. l. amplexicaul, lanceolate; lower ones sub-serrate, smooth; those of the branches linear squarrose. h. 3ft. North America.
A. æstivus (summer-flowering).* fl.-heads blue. July. l. lanceolate, somewhat amplexicaul, narrowed at the end, scabrous at edge. Stem erect, hispid; branchlets pilose. h. 2ft. North America, 1776.
A. albescens (whitish). fl.-heads purple or whitish, nearly 1in. across; corymbosely panicled; scales of involucre ovate-linear, apiculate; ray twenty-flowered. August. l. lanceolate on short petioles, denticulate, downy. Plant beset with rusty down. h. 3ft. Nepal, 1842.
A. alpinus (alpine).* fl.-heads bright purple, 1in. to 2in. across; scales of involucre nearly equal, lanceolate, bluntish. July. l., radical ones lanceolate-spathulate; those of the stem lanceolate. Stem one-flowered. h. 6in. to 9in. Europe, 1658. A very attractive species, having a dwarf, stout habit; it forms a useful and handsome subject for edging, and its flowers are valuable for cutting purposes. See Fig. 177.
A. a. albus (white).* fl.-heads white, in other respects resembling the type; but it is much less desirable, and has not nearly so vigorous a habit. Europe, 1827.
A. altaicus (Altaian).* fl.-heads blue-purple, about 2in. across; stem simple, corymbose, downy. June, July. l. linear-lanceolate, entire, blunt mucronate, three-nerved at base, veiny. h. 1ft. Siberia, 1804. This, which is frequently considered a variety of A. alpinus, is one of the handsomest.
A. alwartensis (Alwart). fl.-heads red; ray very fine; involucre loosely squarrose. May. l. ovate, narrowed at base, entire, about five-nerved. h. 1ft. Caucasus, 1807.
A. Amellus (Amellus).* fl.-heads purple, solitary, numerous; involucre imbricated squarrose; leaves blunt; inner membranous, coloured at edge. August. l. oblong-lanceolate, scabrous. h. 2ft. Italy, 1596. One of the best border kinds.
FIG. 177. ASTER ALPINUS.
A. A. bessarabicus (Bessarabian).* A most desirable variety, frequently seen in gardens; it is rather taller than the type, with larger flower-heads, of a deep purple colour. One of the showiest of all the Asters. See Fig. 178.
FIG. 178. ASTER AMELLUS BESSARABICUS.
A. amplexicaulis (stem-clasping). fl.-heads violet. July. l. ovate-oblong, acute, amplexicaul, cordate, serrated, smooth. Stem panicled, smooth; branches one to two-headed. h. 3ft. North America.
A. amygdalinus (Almond-leaved). fl.-heads white; involucre closely imbricated. August. l. lanceolate, narrowed at base, acuminated, scabrous at edge. Stem simple, corymbose at end. h. 2ft. North America, 1759.
A. argenteus (silvery).* fl.-heads purple. August. l. oblong-lanceolate, silky, sessile. Stem slender, decumbent, loosely branched; branches and branchlets one-headed. h. 1ft. North America, 1801.
A. bellidiflorus (Daisy-flowered). fl.-heads pale red; involucre with spreading scales. September. l. amplexicaul, narrow-lanceolate, scabrous above, lower sub-serrated. Stem much branched. h. 3ft. North America.
A. Bigelovii (Bigelow's).* fl.-heads corymbose, 2½in. diameter, ray-florets lilac, disk yellow. Summer. l. scabrous pubescent, oblong-spathulate; cauline ones amplexicaul, ovate-oblong, crenate, obscurely-toothed. h. 2½ft. Colorado, 1878. A very handsome biennial species. SYN. A. Townshendi.
A. blandus (charming). fl.-heads pale purple; racemes scarcely longer than the leaves. October. l. sub-amplexicaul, oblong-lanceolate, acuminate, sessile, smooth. Stem pyramidal. h. 2ft. North America, 1800.
A. canescens (hoary). fl.-heads pale purple; involucre imbricated, very acute, longer than disk. September. l. linear. Panicle corymbose, much branched, leafy. h. 2ft. North America, 1812. Biennial or perennial.
A. cassiarabicus (Arabian Cassia). fl.-heads pink; panicles corymbose. September. l. ovate, acute, serrated, tapering at the petioles. Plant erect, pilose. h. 2ft. Russia, 1834.
A. caucasicus (Caucasian).* fl.-heads purple, solitary; scales of involucre nearly equal, linear. July. l. ovate, sessile, scabrous. h. 1ft. Caucasus, 1804.
A. ciliatus (ciliated). fl.-heads white. September. l. ciliated; cauline ones linear-lanceolate, nerved; those of the branches very short lanceolate, three-nerved. Stem branched, downy; branches downy. h. 3ft. North America.
A. concinnus (neat).* fl.-heads purple; involucre closely imbricated. October. l. sub-amplexicaul, lanceolate; lower ones sub-serrate, smooth. Stem simple, panicled at end. h. 2ft. North America, 1800.
A. concolor (one-coloured). fl.-heads purple; raceme terminal. October. l. oblong-lanceolate, hoary on each side. Stem simple, erect, downy. h. 1ft. North America, 1759.
A. conyzioides (Conyza-like). Synonymous with Seriocarpus conyzioides.
A. cordifolius (heart-leaved). fl.-heads blue, small, disposed in crowded racemes, which are slightly drooping. July. l. cordate, pilose beneath, finely serrated, stalked. Stem smoothish, panicled; panicle spreading. h. 2ft. North America, 1759.
A. coridifolius (Coris-leaved). fl.-heads pale blue. October. l. very numerous, linear, blunt, reflexed, hispid at edge. Stem branched, diffuse, smooth; branches one-headed. h. 1ft. North America.
