Tanacetum 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 : 169-170

69. Tanacetum L. 2

Annuals or herbaceous perennials, often aromatic. Leaves pinnately divided, alternate. Capitula in terminal corymbs, rarely solitary, with or without ligulate florets. Involucral bracts in 3 rows. Receptacle convex to subglobose, usually punctatetuberculate. Outer florets ligulate, usually female, white or yellow, or tubular, hermaphrodite or female, yellow. Inner florets hermaphrodite, tubular. Achenes all similar, usually 3- to 10- ribbed, without epicarpic mucilaginous cells or vallecular secretory canals, very rarely with secretory lacunae. Pappus usually a corona.

1 All florets tubular 2 Perennial; leaves more than 5 cm 1. vulgare 2 Annual; leaves less than 3 cm 3 Greyish-sublanate, much-branched; lower cauline leaves

0-5-1 cm, the lobes obtuse 2. microphyllum 3 Greenish-pubescent; cauline leaves more than 1 cm, the lobes acute 3. annuum 1 Outer florets ligulate, the ligules sometimes very short 4 Ligules yellow 5 Capitula usually solitary; involucre 10-18 mm in diameter

7. bipinnatum 5 Capitula few to numerous; involucre 4-7(-10)mm in diameter 6 Ligulate florets few, the ligules 0-5-1 (-1-5) mm 7 Capitula hemispherical; leaves white-tomentose 8. santolina 7 Capitula elongate-subglobose; leaves glabrous to subglabrous 5. paczoskii

6 Ligulate florets numerous, the ligules 1 -3 mm 8 Involucre 4-7 mm in diameter, glabrous or sparsely hairy;

outer bracts ovate-lanceolate 4. achilleifolium 8 Involucre 7-10 mm in diameter, lanate, rarely glabrous;

outer bracts broadly ovate 6. millefolium 4 Ligules white 9 Involucre 4-7 mm in diameter; capitula very numerous in a dense, compound corymb 13. macrophyllum 9 Involucre more than 8 mm in diameter; capitula 1-30 in a lax corymb 10 Cauline leaves sessile 11 Capitula long-pedunculate, forming a regular, lax corymb; leaves pubescent to glabrous 9. corymbosum 11 Capitula shortly pedunculate, forming an irregular corymb; leaves densely villous-lanate 10. mucronulatum 10 Cauline leaves petiolate 12 Involucre 12—18 mm in diameter; capitula solitary; leafsegments narrowly lanceolate to oblong-lanceolate,

densely silvery-sericeous 14. cinerariifolium 12 Involucre 6-8 mm in diameter; capitula 3-30 in a lax corymb; leaf-segments oblong or oblong-elliptical to ovate, pubescent to subglabrous

13 Stems ridged; leaf-segments oblong-elliptical to ovate;

ligules 2-5-7 mm 11. parthenium

13 Stems terete; leaf-segments oblong; ligules 7-10 mm

12. parthenifolium