Carum (Apiaceae for Flora Nordica)

Linnaeus, Sp. pl.: 263 (1753). – Type: Clifford Herbarium 106, Carum 1 (BM) lectotype, sel. by Reduron & Jarvis, Regnum Veg. 127: 30 (1993).

Hemicryptophyte (biennial). To 85 cm, with a 4.5–13 mm thick taproot. Stem solid or rarely hollow; basal part 2.5–6(–8) mm thick, angled or sulcate, rarely terete, straw-coloured or slightly purplish, ± glaucous; upper internodes angled or sulcate. Leaves 4–8 at the base and 6–9(–11) on the stem (the innermost basal leaf or the lowest stem leaf is the largest); sheath rather broad, usually purplish, upper leaf-sheaths have a distinct membranous border with rounded tips and a pair of pinnatifid, 0.5–2(–2.8) cm long leaf-lobes at the base; petiole 3–13(–20) cm; blade (1–)2-pinnate, 5–17 × 1.5–6.5 cm, with a length/width ratio of (1.5–)2.2–3.8(–4.8). Primary leaflets sessile, 6–11 (mostly 7) pairs; angle leaflet/rachis 55–90°. Ultimate leaflets (2--)3-pinnatifid with 4–6 pairs of primary lobes; petiolule 5–11 mm; blade 6–19(–28) × 5–24 mm, with a length/width ratio of 0.9–1.3(–1.5); base broadly cuneate to cordate; apices acute or sometimes acuminate, usually purplish. Ultimate lobes on lower leaves (0.8–)1.3–3.3(–4) × 0.5–1.3 mm (length/width ratio 1.3–4), on upper leaves 5–18 × 0.3–0.9 mm, with a length/width ratio of 11–30(–40).

Umbels flat to slightly concave, 3–5 cm high and 4–11 cm wide; peduncle 3–12 cm; rays straight, 2.4–5.4 cm, glabrous. Bracts absent or 1–4, with or without a membrane similar to that of the sheath of the upper leaves, persistent, 2–13(–18) × 0.2–0.6 mm (excluding membrane). Umbellules 8–17; pedicels 0.8–1.4 cm, glabrous. Bractlets absent, or rarely 1–2(–6). Flowers 13–26 per umbellule; petals white or sometimes pale to dark red, with a brown-red midrib, 1.1–1.8 × 0.9–1.7 mm, emarginate (apical cut 0.2–0.6 mm deep); anthers 0.35–0.5 mm; filaments 0.9–1.9 mm. Fruit elliptic in outline, slightly laterally flattened; carpophore flattened, divided or partly entire. Mericarps 3.3–4.3 × 0.8–1.2 × 0.9–1.1 mm, with a length/width ratio of 3.1–4.1(–4.9); ridges 5, pale, low and narrow; valleculae as wide as the ridges, each with 1 brown vitta; stylopodia conical to slightly flattened, 0.4–0.5 mm wide; styles 0.6–0.8 mm, deflexed. – Early summer to mid-summer.

Distribution. Nem–MBor(–LAlp). Alt. 1230 m (N Ho) – Probably not native anywhere in Norden but cultivated and naturalized since long (introduced in the 14th century in southern S); the species is still grown, now partly for ornament (red-flowered forms); possibly also recently introduced with grass seed. – D rather common, though less so in western VJy and parts of SJy. N common in most of the area but rare at the very coast from southern Ho to northern SF, in alpine areas and in VFi and ØFi. S very common north to Dlr and Gst (but slightly less common in the nutrient-poor areas in inner Hl, southwestern SmI and southeastern Vg), further north common along the coast, more scattered and partly a newcomer in the inland (but poorly documented); fairly rare in the mountains. F common to scattered north to central parts of PeP and Ks, rare but still partly archaeophytic further north to KiL and SoL; a more recent anthropochore in EnL and InL. Fa Sandoy and northwestern Streymoy. I scattered to common in coastal provinces.

Habitat. On dry to moderately damp gound (northwards mainly in dry sites); light-open habitats on mineral soil as well as on mull, strongly favoured by a high nutrient level, and avoiding the most base-poor areas. Mainly in places heavily influenced by man, such as farms, leys, lawns, footpaths, roadsides and railway areas (in southern F locally very common on highway embankments), but also in moderately disturbed habitats such as pastures, damp meadows, and even tall-herb woodland (S Hrj).

Biology. Umbellules of primary and secondary umbels with large flowers female and small flowers male; outer umbellules of tertiary umbels with large flowers bisexual and small flowers male, inner umbellules usually only with male flowers. – The fruit contains essential oils and is used as a spice in food and beverage and for medicinal purposes (French 1971).

Variation. Carum carvi is rather variable in size and leaf shape. Large individuals tend to have unusually wide leaf-lobes, and often they have also several bracts. These morphotypes may derive from cultivation. Morphotypes with pale pink to pink petals occur all over Norden but are more frequent in the northern parts.

Similar taxa. Carum carvi fruits have a characteristic scent. The leaves may resemble those of other taxa with narrow leaf-lobes (e.g. Bunium bulbocastanum, Conopodium majus, Chaerophyllum bulbosum and C. prescotti, Daucus carota ssp. carota, Anethum graveolens, Foeniculum vulgare, Seseli libanotis or narrow-lobed Pimpinella saxifraga); C. carvi leaves are glabrous and elongated (length/width ratio usually greater than 2), with lobes at the base of upper leaf-sheaths, and sessile primary leaflets, while all the others have petiolulate primary leaflets (except S. libanotis, with hairy leaves and usually broader lobes) and a leaf length/width ratio less than 2 (except D. carota ssp. carota, with bristly leaves, P. saxifraga, with somewhat broader lobes, and S. libanotis). – See also Selinum carvifolia.