Petrorhagia (Ser. ex DC.) Link

35. Petrorhagia (Ser. ex DC.) Link View in CoL 2

Annual or perennial herbs. Inflorescence paniculate to capitate. Bracts present or absent. Calyx 5-toothed, 5- to 15-veined with scarious commissures. Petals 5, exceeding the calyx, with or without claw; coronal scales absent; stamens 10; styles 2. Capsule dehiscing with 4 teeth. Seeds dorsiventrally compressed; embryo straight. (Incl. Tunica auct.; Kohlrauschia Kunth. ) It is not practicable to make a clear distinction, as is done in Dianthus (vide p. 188), between epicalyx-scales and bracts. The term ‘b ract’ is therefore used to cover both. All species occur in dry calcareous or sandy habitats. Literature: P. W. Ball & V. H. Heywood, Bull. Brit. Mus. (Bot.) 3: 121-72 (1964). 1 Bracts present; inflorescence often capitate or fasciculate 2 Flowers solitary or fasciculate; bracts usually distinctly shorter than the calyx; stems usually much-branched 3 Stems glandular-pubescent at least at the base; calyx-teeth

± triangular, acute or sub-obtuse 8. fasciculata 3 Stems eglandular; calyx-teeth oblong, obtuse 9. saxifraga 2 Flowers in a capitulum; bracts ±completely enclosing the calyx; stems simple or with few branches at the base 4 Largest bracts not more than 4 mm wide; petals linearspathulate, white, with pink or purple veins 5 Calyx-teeth oblong, obtuse, glabrous 11. thessala 5 Calyx-teeth ± triangular, acute, pubescent 12. dianthoides 4 Largest bracts usually at least 4 mm wide; petals with a long claw and distinct limb, pink or purplish 6 Seeds not more than 1-3 mm, covered with cylindrical papillae; leaf-sheaths at least twice as long as wide

15. velutina 6 Seeds at least 1-3 mm, reticulate or covered with low tubercles, or almost smooth; leaf-sheaths less than twice as long as wide 7 Petal-limb crenate or laciniate; seeds 1-7-2-2 mm, almost smooth 16. glumacea 7 Petal-limb obcordate; seeds rarely more than 1-8 mm,

reticulate or tuberculate

8 Seeds reticulate 13. prolifera

8 Seeds tuberculate

9 Outermost bracts mucronate; petal-limb 2—3(—3-5) mm

wide; stems often densely tomentose in the middle

14. nanteuilii

9 Bracts all obtuse; petal-limb up to 4-5 mm wide; stems glabrous 16. glumacea 1 Bracts absent; flowers solitary, rarely fasciculate 10 Petals emarginate 11 Calyx-teeth oblong, obtuse; petals usually pink or reddish

10. graminea 11 Calyx-teeth triangular-oblong, ± acute or mucronate; petals white, sometimes with pink veins 12 Calyx-teeth 3-veined, the lateral veins sometimes feeble near the apex; seeds c. 1-5 mm, black, smooth 4. candica 12 Calyx-teeth 1-veined; seeds c. 1 mm, blackish-brown,

± tuberculate 8. fasciculata 10 Petals entire 13 Annuals, without non-flowering rosettes 14 Glandular-pubescent; calyx-teeth 3-veined 5. eretica 14 Glabrous; calyx-teeth 1-veined 6. alpina 13 Perennial, ±caespitose and woody at the base, with nonflowering rosettes 15 Petals pink; seeds blackish-brown, reticulate-tuberculate

7. phthiotica 15 Petals white or yellow, sometimes with pink veins or purplish spots at the base; seeds black, smooth 16 Stems glandular-pubescent at the base and apex, glabrous in the middle; calyx-teeth strongly 3-veined

3. armerioides 16 Indumentum of stem variable, but never as above; calyxteeth 1-veined (rarely with feeble lateral veins)

17 Stems densely glandular-pubescent throughout, or glabrous in the lower part, rarely completely glabrous;

flowers white or pale yellow, usually with purple anthers 1. illyrica

17 Stems densely glandular-tomentose at the base; usually glabrous in the upper part; flowers yellow, with white anthers 2. ochroleuca