Smyrnium olusatrum L.

Abstract

Tribe Smyrnieae. A stout, glabrous, celery-scented, semelparous, facultative biennial herb with thickened tap-root 50-60 cm and finer lateral roots near surface. One or more solid stems 50-150(-180) cm, becoming hollow at fruiting; branches in upper part often opposite. Furrows more apparent and deeper on upper stems. Leaves 2-3-pinnate or -ternate, dark green and glossy; lobes 25-80 mm, ovate to rhombic, serrate or lobed, with obtuse teeth, all stalked. Stem leaves with expanded sheathing petioles. Compound umbels axillary and terminal, subglobose with (3-)4-15(-18) rays (1-)4(-5) cm long with peduncle usually longer than rays. Terminal umbels with male and hermaphrodite flowers in ratio of about 4 : 1; lateral umbels mostly male. Hermaphrodite flowers can produce viable seed. Bracts and bracteoles entire, few or absent. Flowers c. 1.5 mm, yellow to yellowgreen, actinomorphic, shortly pedicellate. Sepals small, stylopodium formed from styles with elongated bases. Black fruit a schizocarp, 7-8 mm, comprising two single-seeded mericarps, broadly ovoid, laterally compressed. Each mericarp with three distinct, sharp ridges and numerous vittae, which exude pungent myrrh-like oil. Air-dry mass of dispersules averages 20.5 mg (Grime et al. 1981) with seeds ranging between 2.5 and 4.0 mg. An introduced species fully naturalized in hedgerows, roadsides, railway embankments, waste places and cliffs, mainly near the sea. Inland sites are frequently associated with old dwellings or ruins, especially monasteries or castles, where it is probably a relic of kitchen gardens. No significant intraspecific variation is known in Britain (Tutin 1980).