Having flower parts, such as petals, sepals, and stamens, in sets of five.
Made up of five parts or divisions.
(botany) In five parts; made up of five parts.
The Apocynaceae have pentamerous flowers.
Origin of pentamerous
From penta- +"Ž -merous.
Pentamerous Sentence Examples
Thus, in many Caryophyllaceae, as Polycarpon and Holosteum, while the calyx and corolla are pentamerous, there are only three or four stamens and three carpels; in Impatiens Noli-me-tangere the calyx is composed of three parts, while the other verticils have five; in labiate flowers there are five parts of the calyx and corolla, and only four stamens; and in Tropaeolum pentaphyllum there are five sepals, two petals, eight stamens and three carpels.
The flowers are hermaphrodite and regular with parts in fives (pentamerous) throughout, though exceptions from the pentamerous arrangement occur.
- Pentamerous symmetry affects the foodgrooves and thecal plates; probably also the nerves and ambulacral vessels, but not the gonads.
The thecal plates, however irregular in some species, always show defined basals and a distinct plate ("radial") at the end of each ambulacrum; they are in all cases so far affected by pentamerous symmetry that their sutures never cross the ambulacra.
38 shows a pentamerous symmetrical flower, with dimerous pistil.