Solidago L.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1976, Flora Europaea. Volume 4. Plantaginaceae to Compositae (and Rubiaceae), Cambridge University Press : 110

3. Solidago L. 1

Perennial herbs with rhizome or short stock. Stems simple up to the inflorescence; non-flowering leaf-rosettes often present.

Leaves alternate, often toothed. Inflorescence fasciculate, thyrsoid, or forming scorpioid or sometimes corymbose panicles; capitula usually numerous, small; florets yellow. Involucre more or less cylindrical, with many rows of imbricate bracts. Ligules 3-20(-25), female; tubular florets hermaphrodite. Achenes manyveined, subterete or angled; pappus-hairs in 1-2 rows, more or less equal, shortly ciliate.

Species of Subgen. Solidago from North America have been grown extensively in gardens and some of these, in addition to those given below, have been reported as naturalized.

Literature: J. R. Beaudry, Naturaliste Canad. 97: 35-42(1970). J. R. Beaudry & D. L. Chabot, Contr. Inst. Bot. Univ. Montreal 70: 65-72 (1957). B. M. Kapoor & J. R. Beaudry, Canad. Jour. Genet. Cytol. 8: 422-443 (1966). G. E. Schultz, Nov. Syst. Pl. Vase. (Leningrad) 10: 248-257 (1973). 1 Leaves rather fleshy, the lower ± amplexicaul; leaf-margins not ciliate, smooth or very minutely scabrid 2. sempervirens

1 Leaves not fleshy and amplexicaul; leaf-margins ciliate or prominently scabrid

2 All but the lowermost capitula sessile or subsessile in terminal clusters, forming corymbose panicles; receptacular pits minutely fimbriate 5. graminifolia

2All capitula with peduncles at least | as long as the involucre,

not forming corymbose panicles; receptacular pits not fimbriate

3 Inflorescence thyrsoid or a terminal panicle with ascending branches; capitula not secund; involucre 4-5-8 mm; leaves with numerous divergent, often indistinct, lateral veins 1. virgaurea

3 Inflorescence a terminal panicle with patent branches; capitula secund; involucre 2-4(-5) mm; leaves with two lateral veins running almost parallel to the midrib for most of its length and distinct beneath

4 Stems densely pubescent or scabrid at least in the upper |; involucre 2-2-8 mm 3. canadensis

4 Stems glabrous, often glaucous except in the inflorescence; involucre 3-2-5 mm 4. gigantea