LITHOSPERMUM ARVENSE

Family:- BORAGINACEAE

Common Names:- Corn cromwell

Synonyms:- Aegonychon arvense, Buglossoides arvensis, Margarospermum

arvense, Rhytispermum arvense.

Meaning:- Lithospermum (Gr) Stone-seed. A name used by the Greek physician

and botanist Dioscorides.

Arvense(L) Of the cultivated/ploughed field.

General description:- Very variable low to medium, somewhat bristly annual;

stem often solitary, erect, little-branched.

Stems:-

a) 10-50(-90) cm.

b) solitary.

c) usually erect, sometimes branched.

d) with sparse stiff bristly hairs (hispid).

Leaves:-

1) Lowest:

a) oblong-spatula-shaped or obovate, obtuse.

b) the others oblong to linear, acute or subacute, usually erect.

2) Cauline:

a) up to 8(-10) mm wide.

b) oblong, obovate-oblong or oblong-spatula-shaped to narrow and parallel-sided

linear.

Flowers:-

a) 5 mm in diam.

b) joined together in a solitary or paired cyme of 10mm.

c) white.

1) Corolla:

a) 6-9·5 mm.

b) funnel-shaped (infundibuliform).

c) with 5 petals fused in the tube.

d) hairless inside and hairy outside.

e) white (rarely purplish).

f) 5 stamens, inserted below the middle of the corolla-tube with very short

filaments, fused with the corolla.

2) Calyx:

a) with 5 green free sepals, covered in hairs, scarcely exceeded by the corolla.

b) calyx-lobes linear or linear-lanceolate, unequal, acute.

Fruit:-

1) Nutlets:

a) 3-4 mm.

b) obliquely ovoid.

c) hard and firmly attached

d) without lateral swellings, rugose.

e) pale brown.

f) attachment scar 1-1.5 mm wide.

Key features:-

1) Nutlets 2·5-4 x 1·5-2·5 mm, with crowded, prominent tubercules.

2) Corolla 6-9·5 mm, white (rarely purplish), funnel-shaped (infundibuliform).

3) Calyx usually equalling or longer than corolla-tube in flower; with long, sparse

hairs.

4) Pedicels cylindrical in fruit.

5) Lobes acute.

6) Receptacle not oblique in fruit.

Habitat:- Cultivated, fallow and waste ground, roadsides, stony slopes.

Distribution:- C to SE Europe and SW Asia to Iran. Widespread but not too

common on Crete.

Flowering time:- Jan-June.

Photos by:- Steve Lenton