Heracleum Sphondylium L.

An erect, usually more or less hispid, mainly polycarpic perennial. Roots white, bruising orange; a taproot in the first year, becoming more divided from the rootcrown region. A system of outer vegetative meristems and associated secondary taproots develops with age, enlarging the root crown. Successive scars of previous stems evident, becoming displaced deeper into the soil with age. Stems 1-5(-9), usually only one in the first year of flowering; up to 200(-300)cm tall, hollow, ridged, often with deflexed, but not closely appressed hairs, particularly near base. Leaves variable, from semi-entire to bipinnate-ternate, rather densely hairy beneath, less so above with a crenate to serrate margin. Cauline leaves alternate, usually 5(-9), often pinnatifid lobes, 4-10(-18)cm long. Petioles more or less hairy and greatly inflated, often purplish, sheathing the stem. Umbels flat or slightly convex, compound, 4-25 cm across, with usually 10-20 hairy, somewhat unequal rays 2- 12 cm long. Peduncle longer than the rays and more or less puberulent. Bracts few or absent; bracteoles usually present, linear, hispidulous and often deflexed. Stem of a determinate growth form, with one apical umbel (the largest up to 25 cm across) and a variable number of lateral umbels (1-9). Smaller tertiary umbels branch from the peduncles of lateral umbels. Flowers hermaphrodite or male, i.e. with aborted female parts. Petals 2-4mm, white, greenish-white or rarely pink; outer flowers of umbel zygomorphic, with larger petals directed outwards. Sepals very small, up to 05 mm. Filaments 2-3 mm long; pollen oval, tricolpate, mean polar axis 38 4Rm; range 36-52 jm (Cerceau-Larrival 1962; Gawlowska 1961; Grace & Nelson 1981). Styles with enlarged base, forming the stylopodium. Fruit (of 2 mericarps) (6-)7-8 (- 10) mm long, obovate to suborbicular and dorsally compressed, smooth or sparsely hairy with a broad commissure. The one-seeded mericarps ('seeds') 08 mm thick, with weak dorsal ridges and winged lateral ridges. Each mericarp with 6 resin canals (vittae), 4 on the outer, dorsal face and 2 on the inner or commissural face, about as long as the fruit, up to 04mm wide near the lower end. The carpophore, made up of the vascular tissue supplying the endosperm, becomes the mericarp attachment at maturity. Pedicels as long as the fruit; adaxial side puberulent. Styles on mature seed about twice as long as the stylopodium, divergent or somewhat recurved, with capitate stigma. Cotyledons abruptly contracted into a petiole (round type; CerceauLarrival 1962). Mean weight of viable mericarp 3-3mg (range 2-10mg).