Echium L.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1972, Flora Europaea. Volume 3. Diapensiacea to Myoporaceae, Cambridge: Cambridge University Press : 97-98

14. Echium L. 2

Annual, biennial or perennial, hispid herbs or shrubs, with tubercle-based setae. Flowers in bracteate cymes, often forming panicles. Calyx lobed almost to the base, sometimes accrescent. Corolla blue, purple, yellow or white, broadly to narrowly infundibuliform, usually with an annulus of 10 minute scales or tufts of hairs, or a flange-like membrane, at the base, but without scales or invaginations above; tube straight; limb usually oblique. Stamens unequal, exserted or included, inserted below middle of corolla. Style exserted; stigma capitate or bifid. Nutlets ovoid-trigonous, erect, rugose, with flat base.

All species, except those for which another habitat is specified, grow in dry, more or less open habitats, such as sand-dunes, roadsides, cultivated fields or dry pastures.

Many taxa are very variable in habit, leaf-shape and indumentum; species limits in a number of cases are still critical.

E. strictum L. fil. , Suppl. 131 (1781) ( E. ambiguum DC. ), an erect shrub with petiolate, hispid leaves with prominent lateral veins, native of Islas Canarias, is reported from Sicilia, but is not known with certainty to be naturalized. E. candicans L. fil. , Suppl. 131 (1781), an erect shrub with densely grey-villous leaves with prominent lateral veins, native of Madeira, has been reported from N.W. Spain, probably as a garden escape; E. marianum Boiss. , Diagn. Pl. Or. Nov. 2(11): 90 (1849) and E. pavonianum Boiss. , op. cit. 91 (1849), also reported from Spain, are probably variants of this species.

Literature: G. Klotz, Wiss. Zeitschr. Univ. Halle (Math.- Nat.) 9(3): 363-377 (1960); 11(2): 293-302; 11(5): 703-711; 11(9): 1087-1103 (1962); 12(2): 137-142 (1963). R. Fernandes, Bol. Soc. Brot. ser. 2, 43: 145-158 (1969); 44: 146-166 (1970). 1 All stamens completely included in corolla-tube

2 Calyx 6-8 mm at anthesis, up to 15 mm in fruit with lobes 3-6

mm wide at the base 17. parviflorum 2 Calyx 5-7 mm at anthesis, up to 10 mm in fruit with lobes

2-3 mm wide at the base 18. arenarium 1 At least 1-2 stamens exserted from corolla-tube

3 Stigma capitate, somewhat bilobed 9. russicum 3 Stigma distinctly bifid

4 Corolla flesh-coloured or yellowish- or bluish-white (usually brown or blue-grey when dry)

5 Inflorescence intricately branched

6 Corolla 13-18 mm; filaments pinkish-red; basal leaves usually oblanceolate, ± rounded at base, usually somewhat strigose 4. asperrimum 6 Corolla 10-12 mm; filaments pale; basal leaves usually

± lanceolate, attenuate at base, usually not strigose

5. italicum 5 Inflorescence ± spike-like

7 Plant usually with a single or a dominant flowering stem,

with stout, asperous to stinging setae

8 Corolla 10—12 mm, usually yellowish- or bluish-white; filaments pale; flowering stem 40-100 cm 5. italicum 8 Corolla 16-18 mm, flesh-coloured; filaments pinkcarmine; flowering stem 60-250 cm 8. boissieri 7 Plant usually with several, ± equal ascending or erect flowering stems with soft setae

9 Corolla 13-16mm, flesh-coloured; basal leaves 40-150

mm 7. flavum 9 Corolla 7-10 mm, bluish-white; basal leaves usually more than 250 mm 6. lusitanicum 4 Corolla blue, reddish-purple, or pink-carmine turning bluepurple (reddish to blue or purple when dry)

10 Corolla 7-10 mm

11 Basal leaves usually more than 250 mm; perennial; stems several to many, arising from beneath basal rosette

6. lusitanicum 11 Basal leaves usually less than 150 mm; biennial; stems 1

to several, arising from centre of basal rosette 10. vulgare 10 Corolla 11-40 mm

12 Corolla subglabrous, hairy on veins and margins only; basal leaves usually broadly ovate to spathulate with prominent lateral veins 11. plantagineum 12 Corolla ± uniformly hairy; basal leaves usually lanceolate to oblanceolate, without prominent lateral veins

13 Calyx 10-17 mm at anthesis, densely villous with long, white hairs and very sparse setae 1. albicans 13 Calyx 5-10 mm at anthesis, without long, white hairs and with ± dense setae

14 Most flowers with 1-2 exserted stamens

15 Stems ascending, with underlayer of forwardly directed or irregularly patent hairs; upper cauline leaves usually oblanceolate to spathulate, attenuate or petiolate at base 12. sabulicola 15 Stems erect, with underlayer of appressed, uniformly deflexed hairs at least in the lower third; upper cauline leaves usually narrowly elliptical, lanceolate or obovate, ± abruptly sessile

16 Calyx 7-9 mm at anthesis, enlarging to 12-19 mm in fruit; corolla 15-40 mm, broadly infundibuliform

13. creticum 16 Calyx 5-8 mm at anthesis, not enlarging in fruit;

corolla 15-25 mm, narrowly infundibuliform

14. tuberculatum 14 Most flowers with 3-5 distinctly exserted stamens

17 Plant whitish or greyish with very dense, patent,

stinging setae; leaves usually l-5-5(-8)m m wide,

linear-oblong or narrowly lanceolate to oblanceolate

18 Corolla 13-14 mm, usually bluish-purple; upper cauline leaves 1-5-3 mm wide, ± linear-oblong 3. humile 18 Corolla 16-22 mm, usually reddish-purple; upper cauline leaves 3-5(-8) mm wide, ± narrowly lanceolate to oblanceolate 2. angustifolium 17 Plant ± greenish with sparse to dense, appressed to patent setae; basal and lower cauline leaves usually

10-30 mm wide, ovate, lanceolate or oblanceolate

19 Stems several to many, robust, ascending, arising from a stout, ± woody stock; upper cauline leaves ovate to broadly lanceolate 20 Perennial; stems and leaves ±greenish; corolla pinkish-violet, the tube dilating gradually 16. rosulatum 20 Biennial; stems and leaves ± greyish and pustulate; corolla clear blue to bluish-violet, the tube ± abruptly dilating at the middle 15. gaditanum

19 Stems 1 to several, ± slender, erect, usually without a stout stock; upper cauline leaves ± narrowly lanceolate of narrowly oblong 21 Corolla 11-19 mm, usually bright blue, with 4-5 long-exserted stamens 10. vulgare 21 Corolla 15-25 mm, usually dark bluish-purple, with 2-4 variously exserted stamens 14. tuberculatum