Conium maculatum L.

Family: Apiaceae

Pertinent Synonyms & Notes (particularly those used in California; go to GRIN for other synonyms)

Note—the entire plant and especially the fruits are toxic if ingested.

Pertinent Common Names (particularly those used in California; go to GRIN for other common names)

poison hemlock

Primary Disseminule Type

fruit segment

Description (diagnostics are in brown)

Fruit a woody schizocarp, broadly ovoid, slightly compressed laterally, 2–4 mm long x 2–3 mm wide x 1.5–2 mm thick, with reflexed style remnants at apex of stylopodium and sometimes a pedicel remnant at base, grayish-brown, consisting of two plano-convex (D-shaped) one-seeded, indehiscent segments (mericarps) that separate at maturity.

Mericarp flat on adaxial side, convex on abaxial side. Abaxial side with five prominent, slightly wavy, obtuse, light-colored, longitudinal ridges; between ridges the surface is granular and wavy-textured. Adaxial side with a central, longitudinal groove formed by inwardly rolled, firm endosperm; surface is granular and wavy-textured. Oil ducts not obvious in cross-section. Seed coat crushed during fruit development.

Embryo linear, located in lower 1/4 of mericarp.

Risk Assessment (codes in yellow or red indicate cause for concern; assessments are current as of mid-2011; click AUQP, NZBORIC, or NZBPI for access to the most recent versions of these databases and possible assessment changes)