achene

Stem simple, 1–2° high; leaves nearly as in the next; pedicels jointed at or below the middle; valves of the fruiting calyx round-heart-shaped, thin, finely reticulated, naked, many times larger than the achene.

Carl Linnaeus was not kidding when he chose the name Ambrosia for it: achene, its nutritious fruit, provides lots of calories to wildlife.

The achene is a dry, one-seeded, indehiscent fruit, the pericarp of which is closely applied to the seed, but separable from it.

Leontodon autumnalis L. Flowers yellow; achenes light brown, linear, with 5 broad, rounded ribs; achene 4–6.5 mm. long, straight or curved, the outer traversed, with low transverse ridges.

The uppermost spike or spikes wholly staminate, the lower one or more pistillate; ovary and achene surrounded by a sac, the perigynium.