Hedwigia

Commelina
Commelina communis flower with typical arrangement of floral parts: 3 staminodes are present above, 3 fertile stamens below with the central one differing in size and form, and a single style emerging between them (curved in this species).
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Monocots
(unranked):	Commelinids
Order:	Commelinales
Family:	Commelinaceae
Subfamily:	Commelinoideae
Tribe:	Commelineae
Genus:	Commelina L.
Type species
C. communis L.
Selected Species
Commelina benghalensis Commelina caroliniana Commelina communis Commelina cyanea Commelina diffusa Commelina erecta Commelina kotschyi Commelina lukei Commelina mascarenica Commelina sellowiana Commelina sphaerorrhizoma Commelina tuberosa Commelina virginica see List of Commelina species
Synonyms
Erxlebia Medik. Hedwigia Medik. Lechea Lour. Ananthopus Raf. Allotria Raf. Dirtea Raf. Eudipetala Raf. Larnalles Raf. Nephralles Raf. Ovidia Raf. Allosperma Raf. Isanthina Rchb. ex Steud. Heterocarpus Wight Disecocarpus Hassk. Omphalotheca Hassk. Phaeosphaerion Hassk. Spathodithyros Hassk. Trithyrocarpus Hassk. Athyrocarpus Schltdl. ex Benth. 1883 not Schltdl. 1855 nor Schltdl. ex Hassk. 1866 Commelinopsis Pichon

Commelina is a genus of approximately 170 species commonly called dayflowers due to the short lives of their flowers. They are less often known as widow's tears. It is by far the largest genus of its family, Commelinaceae. The Swedish taxonomist Carl Linnaeus of the 18th century named the genus after the two Dutch botanists Jan Commelijn and his nephew Caspar, each representing one of the showy petals of Commelina communis.

The dayflowers are herbs that may be either perennial or annual. They are characterised by their zygomorphic flowers and by the involucral bracts called spathes that surround the flower stalks. These spathes are often filled with a mucilaginous liquid. Each spathe houses either one or two scorpioid cymes, with the upper cyme being either vestigial or bearing from one to several typically male flowers, and the lower cyme bearing several flowers. All members of the genus have alternate leaves.

The Asiatic dayflower (Commelina communis) is probably the best known species in the West. It is a common weed in parts of Europe and throughout eastern North America. Several species, such as Commelina benghalensis, are eaten as a leaf vegetable in Southeast Asia and Africa.

Plants in the genus are perennial or annual herbs with roots that are usually fibrous or rarely tuberous or rhizomatous. The leaves are distichous (i.e. 2-ranked) or spirally arranged with blades that either lack or have a petiole. The ptyxis, or the way the leaf is folded in the bud, is either involute (i.e. having inrolled margins) or supervolute.

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Wikipedia