Commelina erecta L. - Day Flower

Commelina erecta plant

Family - Commelinaceae

Stems - Erect to ascending, herbaceous, multiple from base, from thick roots, glabrous to sparse pubescent near apex, often with reddish-purple striations, branching, to -1m long.

Leaves - Alternate, sheathing, lanceolate to lance-oblong, attenuate, entire, undulate or not, glabrous, to +11cm long, to +/-2.5cm broad. Margins often reddish. Ocrea scarious-green, with rounded lobes at apex or not. Lobes to 2.5mm long. Margins of the ocrea typically with white cilia.

Commelina erecta leaves

Commelina erecta auricleAuricle.

Inflorescence - Terminal cymes of +/-3 flowers. Cymes subtended (surrounded) by a folded spathe. Spathe margins joined in basal 1/3 to 1/2. Spathe pilose to scabrous because of hispidulous hairs, to 2.5cm long, 2cm broad (when folded), acute.

Commelina erecta spatheSpathe.

Commelina erecta spatheArrow shows joined base of scape.

Flowers - Petals 3. 2 upper petals blue, clawed. Claw to 3mm long, white. Limb (sub)orbicular to reniform, to 1.7cm in diameter, glabrous. Lower petal white, reduced, notched at apex, +/-6mm long, 7-8mm broad, often scarious, glabrous. Staminodia 3. All exserted by upper petals. Anthers yellow, 4-lobed. Filaments glabrous, pale yellow to white, to 4mm long. Stamens 3, unequal, one similar to staminodia (and exserted just beyond them), other two more "typical" and exserted by lower petal. Filaments of two "typical" stamens glabrous, to 1.4cm long, lilac, curling inward at apex. Anthers purplish, 2mm long. Style curling at apex, to 5mm long, glabrous, white. Ovary green, 1mm in diameter, 3-locular. Sepals 3, whitish, reduced.

Commelina erecta flowerFlower.

Commelina erecta stamensClose-up of flora organs.

Flowering - May - October.

Habitat - Sand and gravel bars, streambanks, wooded slopes, bluffs, glades, roadside ditches.

Origin - Native to U.S.

Other info. - This species is frequent in the lower 1/2 of the state but is found is several more counties scattered throughout our area. The species has the typical flowers of the genus and has erect stems, (hence the species name), which makes it easy to ID in the field.
Steyermark and other authors break the species apart into as many as 3 or more varieties and as many forms. These varieties are determined by leaf width or spathe size. Some integration occurs.
For the origins of the genus name, see C. communis in this same section of this website.

Photographs taken in Winter Haven, FL., 6-27-02, and at Millstream Gardens Conservation Area, Madison County, MO., 7-17-04.


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