thyrse n : a dense flower cluster (as of the lilac or horse chestnut) in which the main axis is racemose and the branches are cymose [syn: thyrsus] [also: therses (pl)]

A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers (and fruit) attached along the secondary branches (in other words, a branched cluster of flowers in which the branches are racemes).

This type of inflorescence is largely characteristic of grasses like oat and crabgrass, as well as other plants such as pistachio and mamoncillo. Botanists use the term paniculate in two ways: "having a true panicle inflorescence" as well as "having an inflorescence with the form but not necessarily the structure of a panicle".

A corymb is similar to a panicle with the same branching structure, but with the lower flowers having longer stems, thus giving a flattish top superficially resembling an umbel. Many species in the Maloideae, such as hawthorns and rowans, produce their flowers in corymbs.

A thyrse is a compact panicle having an obscured main axis and cymose subaxes, making its paniculate nature hard to discern. Many Ceanothus species have thyrsiform inflorescences, notably Ceanothus thyrsiflorus.

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