Centranthus DC.

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 : 55

5. Centranthus DC. 1

Glabrous, usually glaucous annual or rhizomatous perennial herbs with erect, usually unbranched flowering stems. Flowers hermaphrodite or unisexual; inflorescence cymose, usually compound, with dense partial inflorescences. Calyx-teeth 5-25, linear, inrolled in flower and accrescent in fruit to form a plumose pappus. Corolla with 5 usually unequal lobes; tube cylindrical or infundibuliform, gibbous near the middle, or spurred near the base and with an internal longitudinal membrane from the insertion of the spur to the mouth. Stamen 1. Stigma entire to 3-fid. Sterile loculi of fruit very small. Literature: I. В. K. Richardson, Bot. Jour. Linn. Soc. 71: 211-234 (1976) 1 Annual; at least the upper leaves ±divided 2 Corolla-tube c. 2 mm, gibbous 7. calcitrapae 2 Corolla-tube (4-)6-8 mm, spurred 8. macrosiphon 1 Perennial; leaves entire 3 Corolla-tube (2—)3—4 mm, gibbous 6. trinervis 3 Corolla-tube (5-)7-18 mm, spurred 4 Corolla-tube (11-)12-18 mm 5 Stems 40-200 cm, branched above; leaves 4-12 cm

4. longiflorus 5 Stems not more than 40 cm, simple or branched only at base; leaves 1-4 cm 5. nevadensis 4 Corolla-tube not more than 10(—11) mm 6 Leaves linear, mostly c. 2 mm wide; corolla-spur 2-4 mm

2. angustifolius 6 Leaves ±lanceolate, (3-)4-30mm wide; corolla-spur

(2—)4—10(—12) mm 7 Leaves 4-6(-12)mm wide, erect or patent; inflorescence capitate; stems usually simple 3. lecoqii 7 Leaves up to 60 mm wide, patent; partial inflorescences several; stems usually branched 1. ruber Sect , centranthus. Perennial. Leaves undivided. Corolla spurred near the base. Stigma entire. Fruit glabrous.