Laserpitium (Apiaceae for Flora Nordica)

Hemicryptophyte (perennial). To 150 cm; taproot 10–17 mm thick. Stem glabrous, frequently distinctly yellowish; basal part 5–10(–15) mm thick, terete, not reddish, ± glaucous; upper internodes terete. Leaves 5–7 at the base and 3–5 on the stem (the innermost basal one is usually the largest); sheath inflated, not purplish, with rounded tips; petiole 11–29 cm; blade unequally 2-pinnate, 16–40 × 16–30 cm (length/width ratio 0.8–1.3), lower side usually distinctly glaucous, glabrous to densely hairy, upper side glabrous. Primary leaflets usually 3 pairs; angle leaflet/rachis 40–60°. Ultimate leaflets entire or rarely with one pair of lobes; petiolule 18–50 mm; blade ovate to almost orbicular, 32–100 × 25–89 mm, with a length/width ratio of 1.1–1.4(–1.7); base distinctly cordate to truncate; apex obtuse or rarely acute; margin obtusely serrate (teeth white to slightly purplish, acuminate to mucronate). Upper leaves often with lanceolate leaflets having entire margins, sometimes without a blade.

Umbels usually slightly convex, 5–9 cm high and 12–22 cm wide; peduncle 15–29 cm; rays straight or slightly bent inwards, 5.2–10.7 cm, usually papillose on the adaxial side. Bracts (3–)5–12, persistent, 10–27(–35) × 0.9–2.7 mm, usually distinctly membrane-bordered. Umbellules 23–47; pedicels 0.8–1.5 cm, papillose on the adaxial side. Bractlets 3–10, persistent, usually inconspicuous and membranous but very unequal in size, 3–15 × 0.1–0.2(–0.6) mm. Flowers not or slightly zygomorphic, (22–)28–45(–54) per umbellule; sepals 0.3–0.7 mm, apiculate; petals white or sometimes light pink, 1.6–3 × 1.1–2.1 mm, emarginate (apical cut 0.2–0.7 mm deep); filaments 2.2–4 mm; anthers 0.6–0.8 mm. Fruit oblong to almost rectangular in outline, not or dorsally slightly flattened; carpophore divided. Mericarps 6.3–8.5 × 4.5–6 × 1.5–3 mm, with a length/width ratio of 1.2–1.6(–1.7); secondary ridges rather pale, developed as straight or sometimes undulating wings, with entire or erose margin, the lateral ones 1.5–2 mm wide, the median ones equally wide or narrower; primary ridges reduced, with short, introrse hairs; stylopodium stipitate, high-arched, 0.7–1 mm wide; style 1.5–2.8 mm, deflexed. – Mid-summer to late summer.

Distribution. Nem–BNem. Subcontinental. – D Sjæ Hornbæk 1889, Dronningmølle 1971 and c. 10 localities west and north of København (probably extant at Nymølle and Søndersø only). N Bu Nedre Eiker, Vf Larvik, Te Porsgrunn, Bamble, AA Birkenes, VA Kristiansand and Søgne. S mainly in the southeastern lowlands: scattered to rather common from eastern Sk and central SmI north to and including Upl (but rare in Bl, southernmost Klm and western Srm); outliers in Sk Brunnby 1924 and Höganäs (early 19th century), Vg Undenäs and the central calcareous plateaus, and Gst (6 localities, still in Hedesunda and Hille); escaped from cultivation and established in e.g. Nrk Lillkyrka (Ekeberg) and Mpd Sundsvall (Norra Stadsberget). F the southwestern archipelago east to V Korppoo (common in A).

C Europe and the mountains of S Europe.

Habitat. Mesic to fairly dry, mull-rich or clayey, not too base-poor soil, usually in light shade. Open deciduous woodland (especially with oak, lime and hazel) and calcareous pine woodland, preferably in boundary zones (e.g. riversides, glades, along paths and roads, small wooded hills in arable fields, wooded meadows). Not thriving in closed forest, but favoured by slight overgrowth (sensitive to grazing and mowing).

Similar taxa. Laserpitium latifolium, with its dull leaves with rounded leaflets, is fairly unique among Nordic umbellifers. Heracleum sphondylium can be similar in habit but has a bristly stem, acute leaflets and umbels without bracts; see also Angelica sylvestris.