Herbs, perennial or annual, spreading. Stems decumbent to scandent. Leaves: blade narrowly lanceolate to lanceolate-oblong, lanceolate-elliptic or ovate, 1.5--14 × 0.5--3.3 cm, margins scabrous, apex acute to acuminate, glabrous. Inflorescences: distal cyme 1--several-flowered, usually exserted; spathes solitary, bright green, without contrasting veins, pedunculate, usually distinctly falcate, (0.5--)0.8--4 ´ 0.4--1.2(--1.4) cm, margins distinct, glabrous or scabrous, sometimes also sparsely ciliate or ciliolate basally, apex usually acuminate, usually glabrous or nearly so; peduncles 0.5--2(--4) cm. Flowers bisexual and staminate; petals all blue (rarely all lavender), proximal petal smaller; medial stamen anther connective usually with transverse band of violet; staminodes 2--3; antherodes yellow, medial often absent or vestigial, cruciform. Capsules 3-locular, 2-valved, 4--6.3 mm. Seeds 5 (or less through abortion), brown, 2--2.8(--3.2) ´ 1.4--1.8 mm, deeply reticulate. The name Commelina nudiflora Linnaeus has been incorrectly used for this species.