Dayflower is a weak-stemmed, straggling perennial growing 1' to 2' tall and somewhat covered with a clear mucilaginous sap.  It is a monocot, and is called dayflower because it is an ephemeral, with the petals wilting into a moist blue mass after a single day.  The stems are thickish and jointed with swollen nodes which often send out fibrous roots when they come into contact with soil.  The leaves are alternate and entire, broadly lanceolate with ± wavy margins, 3/4" to 1-1/2" long and up to 1" wide, parallel-veined, and have short hairs on both surfaces, especially on the underside midvein.  There are no petioles; instead the leaves clasp the nodes of the stem with a thin membranous sheath which has reddish hairs on the margin.  The flowers are enclosed in or arise from a spathe, which is a bract or pair of bracts that form a small envelope, and consist of three petals, two dark blue that are fan-shaped and strongly clawed, and and a smaller one opposite that is a paler blue or white in some species. There are three sepals, cup-shaped, rounded and somewhat translucent or green.  The ovary is superior and there is a single blue style with a tiny capitate stigma and six stamens with glabrous filaments.  On the species which I examined, it appeared that there were four shorter stamens with bright yellow anthers and two longer stamens with ± bluish anthers. I understand that in this genus there are often staminodes or sterile stamens, but I was unable to determine that for this species.  This species of dayflower is also reported to have cleistogamous ( or self-fertilizing) flowers on the underground stems.  Late summer and fall appears to be the customary blooming period for the dayflowers, which are native to tropical Asia but have a worldwide range and are seen in cultivation or as an escape.

Click here for Latin name derivations: 1) Commelina 2) benghalensis.
Pronunciation: kom-el-EYE-na ben-gal-EN-sis.
Click here for Botanical Term Meanings.