Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.
1 Corolla yellow; rays 15-40; plants 5-21 dm tall; fruits ca. 2× as long as wide; [naturalized aromatic culinary herbs of upland situations]. |
..2 Petiolar sheaths of the principal leaves 1-2.5 (-3) cm long; mericarps dorsally flattened, at least the lateral ribs thin-winged; fresh plants with dill odor; annual |
..2 Petiolar sheaths of the principal leaves 3-10 cm long; mericarps subterete or slightly laterally flattened, the ribs not winged; fresh plants with fennel odor; biennial or perennial |
1 Corolla white; rays 5-20; plants 1-15 dm tall; fruits either 4-5× as long as wide (narrowly oblong), or 0.5-1.5× as long as wide ovoid, spherical, or strongly bilobed and wider than long; [native or naturalized herbs of upland or wetland situations]. |
....3 Mericarps (and ovary) ornamented with tubercles, spines, or sharp-pointed projections ("scabes"), in addition to the ribs (use at least 10× magnification). |
......4 Schizocarp ovoid-oblong to urceolate-ovoid or broadly ellipsoid, ribs sparsely to densely scaberulous with single-celled papilla-like projections |
......4 Schizocarp broadly ovoid to ellipsoid or elliptic-ovoid, ribs and intervals variously hairy or at least tuberculate |
....3 Mericarps (and ovary) glabrous. |
........5 Umbels leaf-opposed; umbels simple to compound. |
........5 Umbels terminal or on axillary branches; umbels compound. |
..........6 Fruits 8-10 mm long, oblong-linear |
..........6 Fruits 1.5-6 mm long, ovoid to subglobose, or strongly bilobed and then wider than long |
............ 7 Fruits distinctly wider than long, 4-7 mm wide, bilobed, each lobe (mericarp) subglobose; outer flowers of each umbellet radiant (the petals larger to the outside of the umbellet) |
............ ..8 Involucre of bracts present (subtending each umbellet); fruit 4-5 mm broad; mericarp ribs evident; [native, AL, AR, OK, LA, and TX] |
............ ..8 Involucre of bracts absent; fruit 5-7 mm broad; mericarp ribs obsolete; [non-native waif, reported from NJ, PA, and MD] |
............ 7 Fruits somewhat longer than wide, 1.5-4 mm wide; outer flowers of umbellets similar in size and form to the inner flowers. |
............ ....9 Umbellets per umbel (=rays) 50-100+; [ballast waif, reported from a few old ports] |
............ ....9 Umbellets per umbel (=rays) 2-30; [collectively widespread and common]. |
............ ......10 Non-sheathing portion of petioles 0-0.5 cm long (the leaf divisions starting at the summit of the sheath) |
............ ......10 Non-sheathing portion of petioles 5-10 cm long. |
............ ........11 Plants annual or biennial; [non-native, weed or waif] |
............ ........11 Plants perennial from tubers; [native from OH, KY, TN, AL westward] |