Omalotheca Cass.

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 : 126

20. Omalotheca Cass. 1

Tomentose perennials with non-flowering shoots. Leaves alternate. Capitula in a racemose or spicate terminal inflorescence, very rarely solitary. Receptacle without scales. Involucral bracts mottled, usually brownish; indurated tissue of the inner bracts entire. Florets tubular, fertile, the outer female, the inner hermaphrodite; hermaphrodite florets reddish-purple at apex. Achenes 1-2 mm, with imbricate papillae and hairs 6-7 times as long as wide, not emitting mucilage in water; pappus present. Pollen-grains with broad furrows, orbicular pores and slender spinules.

Literature: vide Gnaphalium . 1 Inflorescence with 10-150 capitula; stem 15-50 cm; pappushairs connate at base, falling as a unit

2 Plant sericeous-tomentose; cauline leaves 1-veined, lanceolate to linear, diminishing steadily in size upwards, the lower 3-8 mm wide, the upper 2-3 mm wide; bracts brownish or stramineous 1. sylvatica

2 Plant ±floccose-tomentose; cauline leaves 3-veined, lanceolate, not diminishing in size until well above the middle of the stem, the lower 8-18 mm wide, the upper 4-8 mm wide; bracts dark brown 2. norvegica

1 Inflorescence with (1—)2—10(—12) capitula; stem 2-20 cm;

pappus-hairs free, falling separately

3 Outer bracts 4-f as long as the involucre; involucre broadly campanulate, with 2(-3) rows of bracts; hairs on achene

2-fid at apex 6. supina

3 Outer bracts |(-i) as long as the involucre; involucre broadly ovoid, with 3 rows of bracts; hairs on achene rounded at apex

4 Involucral bracts not stellate in fruit; lobes of the corolla in hermaphrodite florets little longer than wide; achenes sparsely patent-hairy, the hairs not covering the base of the pappus 3. hoppeana

4 Involucral bracts stellate in fruit; lobes of the corolla in hermaphrodite florets much longer than wide; achenes densely appressed-hairy, the hairs covering the base of the pappus

5 Cauline leaves± abruptly tapered to the apex; inflorescence rather compact; peduncles not longer than capitula; involucral bracts rounded above 4. roeseri

5 Cauline leaves very gradually tapered to the apex; inflorescence very lax; peduncles of lower capitula longer than the capitula; involucral bracts subacute 5. pichleri