trimerous


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Related to trimerous: tetramerous

trimerous

[′trim·ə·rəs]
(botany)
Having parts in sets of three.
(invertebrate zoology)
In insects, having the tarsus divided or apparently divided into three segments.
References in periodicals archive ?
He also hypothesized that ancestral flowers were bisexual and trimerous, each with six tepals and six stamens in two whorls, and a tricarpellate gynoecium.
Staminate flowers symmetrical, trimerous, not widely open at anthesis, sepals 3 short, imbricate, free, petals 3, valvate, stamens 6, slightly exceeding petals at anthesis, anthers small, dorsifixed, oval-linear with sagittate base, pistillode reduced.
The flower of Cyperoideae is tetracyclic with two alternating whorls of three perianth members, one whorl of three stamens opposite the outer perianth parts, and a trimerous gynoecium (Vrijdaghs et al., 2005a, 2009).
Staminate flowers light yellow when fresh; sepals 3, ovate, 1 mm long, connate for 1/2 their length, lobes reaching 1/2 to the total height of the corolla tube; petals 3, ovate-acuminate, 4-7 mm long, including a 1 mm long acumen, connate up to 1-1,5 mm (1/6-1/4 of their length); stamens 12-15, 1-3 opposite each sepal and 2-3 opposite each petal, filaments 1-1,5 mm long, anther 2-2,2 mm long, round at apex; pollen elliptical, monosulcate, tectate, 25,65 [+ or -] 1,01 um diam, exine reticulate, exine thickness 0,52 [+ or -] 0,10 um, with reticule aperture 0,75 [+ or -] 0,43 um diam, reticule width 0,48 [+ or -] 0,06 um; pistillode trimerous, minute.
Corolla merosity: trimerous = 0; tetramerous = 1; pentamerous = 2; hexamerous = 3; octamerous = 4.