SPECIES DESCRIPTION
TRIFOLIUM NIGRESCENS
Family and Genus:- See- LEGUMINOSAE/Subgen. LOTOIDES/Sect.
Common Names:- Annual white clover
Homotypic Synonyms:- Amoria nigrescens.
MMeaning:- Trifolium (L) With three leaflets.
Nigrescens (L) Blackish, darkening, turning black.
General description:- Glabrous to sparsely pubescent annual.
Stems:-
1) 5-40 cm, 5-40 cm, erect or ascending, often branched at base, 1-2(-3 mm)
thick.
Leaves:-
1) Leaflets, 8-15(-25) mm, obovate or obcordate denticulate in upper half. often
emarginate.
2) Stipules, triangular-lanceolate, acuminate, free part abruptly contracted into a
linear appendage.
Flowers:-
1) Heads, 10-20 mm wide, globose, lax; stalks of the inflorescence.
2) Peduncles, longer than the leaves; pedicels equalling or longer than the calyx-
tube, deflexed in fruit.
3) Calyx:
a) tube, glabrous,10-veined.
b) teeth, lanceolate or linear, without wide sinuses between, upper, usually
slightly longer than the others and equalling or exceeding the tube.
4) Corolla, 6-9 mm, white, cream or pink, thin and shrivelled in fruit.
5) Style, less than 1.5 times as long as the ovary at anthesis, thin.
6) Ovules, (3-)4(-6).
Fruit:-
1) Legume, 1- to 5-seeded, slightly constricted between the seeds.
Key features:-
1) Upper 2 calyx-teeth, equalling or only slightly exceeding the tube.
2) Heads, 10-20 mm wide.
3) Corolla, 6-9 mm.
Habitat:- Seasonally wet habitats, field margins. 0-1100 m. (occasionally higher).
Distribution:- Throughout Greece, but less common in the E Aegean area.
Widespread across Crete.
Flowering time:- Mainly Apr-June.
Photos by:- Steve Lenton
