ASPERULA ARVENSIS

Family and Genus:- See- RUBIACEAE

Common Names:- Blue Woodruff.

Homotypic synonyms:- Galium arvense; Galium sherardiiflorum.

Meaning:- Asperula (L) Asper, rough, with a diminutive ending, referring to the rough surface of some members of the genus.
                  Arvensis (L) Of cultivated fields.

General description:- An erect annual with narrow whorled leaves and terminal heads of small blue to lilac flowers.

Stems:-
1) Shoots, usually 10-30 cm tall, erect and branched.
2) Surface, four-angled, generally glabrous.

Leaves:-
1) Cauline, sessile, the middle and upper leaves forming apparent whorls of 6-8.
    a) blade, linear-lanceolate, usually 1-2.5 cm long.
    b) apex, blunt to shortly pointed.
    c) surface, glabrous or very shortly hairy; margins entire.
2) Whorls, composed of opposite true leaves and similar enlarged stipules.

Flowers:-
1) Inflorescence, compact terminal heads.
2) Bracts, numerous, forming a conspicuous involucre around each head; margins
    ciliate.
3) Calyx, limb absent or inconspicuous.
4) Corolla, blue to lilac;
    a) tube, about 4 mm long and usually 4 spreading lobes.
    b) lobes, 4 spreading
5) Stamens, 4, inserted on the corolla tube and alternating with its lobes;
    a) filaments, short.
    b) anthers, 2-celled.
6) Ovary, inferior, 2-celled, with one ovule in each cell;
    a) style, divided into 2 branches, each ending in a capitate stigma.

Fruit:-
1) Schizocarp, dry, separating into 2 one-seeded mericarps.
2) Mericarps, about 3 mm long, granular on the surface, glabrous or sparsely hairy.

Distinguishing features:- The annual habit, blue tubular flowers and conspicuous involucral bracts distinguish this species from Asperula cynanchica. Confirm identification against Asperula orientalis when assessing cultivated plants or garden escapes.

Flowering time:- May to July; timing may vary in casual British occurrences.

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Toxicity:- Species-specific toxicity information is insufficient to establish the safety of ingestion or medicinal preparations.

Habitat:- Cultivated fields and disturbed open ground; in Britain associated with imported grain, bird-seed and waste ground.

Distribution:- Introduced and sporadic in Great Britain and Ireland. Native across the Mediterranean region and parts of central Europe eastwards to central Asia.

Conservation status:- No Great Britain threat category was located in the 2025 vascular-plant Red List. British records are of an introduced casual, including bird-seed and grain aliens.

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