Chaerophyllum tainturieri Hooker [includes the essentially glabrous var. tainturieri and the pubescent var. dasycarpum], wild chervil. Annual, taprooted, not rosetted, 1–stemmed at base, with ascending flowering shoot from each cauline node, in range to 55 cm tall; shoots with to 3 short–lived basal leaves and several highly dissected cauline leaves, eventually with an inflorescence formed at each leaf–bearing node, short–hirsute and hirsute or essentially glabrous (pubescent on lower half of plant), when crushed with a faint, carrotlike (Daucus) smell.
Stems to 13–ridged, to 3.5 mm diameter, tough, with all ridges descending from leaf, internodes swollen approaching each node, finely striped green and colorless (ridges).
Leaves helically alternate, odd–2—3(—4)–pinnately dissected, blade bilaterally symmetric having a terminal primary lobe and 1—4(—5) opposite pairs of lateral primary lobes, petiolate with sheath, without stipules; petiole sheathing node and not closed, channeled, to 100 mm long, sheath of lower leaves with wide membranous margins, if petiole short enough then membranous wings fused to the lowest pair of petiolules, sometimes ciliate and wavy; blade to 80 mm long, blade ≤ petiole; rachis and other axes channeled; primary and paired secondary lobes ± ovate to obovate in outline, pinnately veined with principal veins sunken on upper surface and midvein raised on lower surface, petiolules 2—5 mm long; secondary to tertiary lobes alternate, ultimate lobes narrowly oblong to narrowly oblanceolate, to 4 × < 0.5 mm, either with hairs or glabrate with some hairs on lower surface.
Inflorescence leafy compound umbel, terminal on principal and axillary shoots, mostly not flat–topped, open, at each node of 1—4 units having either all stalked umbellets or mixed with 1—2 continuing shoots, many–flowered, umbellet of 3—8 bisexual flowers, bracteate, short–hairy to glabrate or glabrous; involucre absent, the bracts at node 0—2 subtending continuing shoots (not subtending stalked umbellets), leaflike, decreasing upward, sheath with wide membranous margins conspicuously ciliate and wavy; peduncle of umbellet at anthesis (0)15+ mm long, aging mostly 4–sided, angles lacking teeth; involucel bractlets of umbellet subtending outer series of pedicels, to 5, initially ascending later widely spreading, elliptic or ovate to obtuse–obovate or oblong and mostly unlobed, 2—4 × 0.8—1.3 mm, (the widest sometimes heart–shaped), minutely toothed above midpoint to short–ciliate on margins, glabrous to short–hirsute; pedicels at anthesis ca. 0.3 mm long increasing in fruit.
Flower bisexual, radial, 1.5—2 mm across; sepals absent; petals 5, in bud curved over anthers later spreading and lacking tail–like tip curved inward, obovate, 0.6—0.8 × 0.4—0.5 mm, white with green midstripe on lower surface, acute to obtuse at tip, without midridge; stamens 5, free, opposite petals; filaments 0.35—0.4 mm long, white; anthers dorsifixed, dithecal, 0.15—0.2 mm long, pale yellow aging reddish, longitudinally dehiscent; pollen pale yellow; pistil 1; ovary inferior, wedge–shaped and 2–lobed, 0.7—1 × 0.5 × 0.3 mm, green, grooved on broad faces, either glabrous or puberulent with ascending hairs, with a pair of green, short–conic platforms (stylopodium, stylar tissue), ca. 0.3 × 0.3 mm on top of ovary, stigmas small at tip of stylopodium.
Fruit schizocarp, of 2 dry, 1–seeded halves (mericarps), 4—8 per involucel, spreading to suberect, before splitting lanceoloid, 6—8.5 × 1.7—1.8 mm with stylopodium on top, mericarps narrowly hemi–lanceoloid, inside face grooved, having 3 prominent and corky ribs on curved outer face and ribs along 2 edges, either glabrous or puberulent with evenly distributed hairs on the back; pedicels markedly unequal in umbellet, to 7 mm long and < fruit, short hairs present or not as on fruit.
A. C. Gibson