Herbs, perennial, robust, spreading, sometimes scrambling in shrubs. Leaves: blade narrowly lanceolate to lanceolate-elliptic, 6--14 ´ 1--3.3 cm, apex acuminate. Inflorescences: distal cyme usually exserted, 1--3-flowered; proximal cyme 2--5-flowered; spathes pedunculate, falcate, 2.3--4 ´ 0.5--1.1 cm, apex acuminate; peduncles 1--2(--4) cm. Flowers blue; medial stamen anther connective without dark band. Capsules 3-locular, 2-valved. Seeds typically only 1--2 developing, dark brown, 2.1--2.8 mm, deeply reticulate. 2n = 90.

Flowering spring--fall (perhaps all year round). Hammocks, streamsides, ditches, cypress swamps, wet woods, and lake shores; introduced; Fla.; Asia.

Commelina diffusa is a very variable species throughout its vast range. I have not been able to match C. diffusa var. gigas with specific herbarium specimens from elsewhere. It probably arrived as an introduction instead of arising from diploid C. diffusa through in situ autopolyploidy.