Commelina

Plumier ex Linnaeus

Sp. Pl. 1: 40. 1753; Gen. Pl. ed.; 5:25, 1754.

Common names: Dayflower widow's-tears
Etymology: for the two Dutch botanists Jan and Kaspar Commelijn, because of the two showy petals
Treatment appears in FNA Volume 22.
 TaxonIllustrator 
FNA22 P37 Commelina pg 194.jpegCommelina erecta
Commelina dianthifolia
Commelina communis
Commelina virginica
Commelina gambiae
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey

Herbs, perennial or annual. Roots thin or tuberous. Leaves 2-ranked or spirally arranged, not glaucous; blade sessile or petiolate. Inflorescences terminal, leaf-opposed; cymes 1–2, enclosed in spathes, proximal cyme several-flowered, distal cyme vestigial or with 1–several staminate flowers; spathes often filled with mucilaginous liquid, margins distinct or basally connate; bracteoles usually absent. Flowers bisexual and staminate, bilaterally symmetric; pedicels well developed; sepals distinct or proximal 2 connate, unequal; petals distinct, proximal petal often different color than distal 2, smaller or subequal, distal 2 blue (occasionally lilac, lavender, yellow, peach, apricot, or white), clawed; stamens (5–) 6, proximal 3 fertile, medial different in form, size from others, distal (2–) 3 staminodial; filaments glabrous; antherodes commonly 4–6-lobed; ovary 2–3-locular, ovules 1–2 per locule, 1-seriate. Capsules 2–3-valved, 2–3-locular. Seeds 1–2 per locule; hilum linear; embryotega lateral. x = 11–15.

Distribution

Almost worldwide, mainly tropical

Discussion

Species ca. 170 (9 in the flora).

Key

1 Spathes with margins distinct to base. > 2
1 Spathes with margins connate basally. > 5
2 Perennials with erect to ascending stems; roots tuberous; leaves linear to linear-lanceolate Commelina dianthifolia
2 Annuals or perennials usually with decumbent to scandent stems; leaves narrowly lanceolate to ovate-elliptic. > 3
3 Spathes generally whitish or pale green toward peduncle with contrasting, dark green veins; proximal petal white or paler than others; capsules 2-locular; seeds rugose pitted-reticulate Commelina communis
3 Spathes without contrasting veins; proximal petal ± concolorous with others; capsules 3-locular; seeds reticulate or smooth to faintly alveolate. > 4
4 Spathes not at all to slightly falcate; distal cyme usually vestigial (rarely well developed, 1-flowered); seeds smooth to faintly alveolate Commelina caroliniana
4 Spathes usually distinctly falcate; distal cyme in larger spathes usually well developed, 1–several-flowered; seeds reticulate Commelina diffusa
5 Flowers apricot- or peach-colored Commelina gambiae
5 Flowers blue (rarely lilac to lavender or white). > 6
6 Leaf sheaths with auricles at summit; roots stout; proximal petal white, minute; locules all 1-seeded Commelina erecta
6 Leaf sheaths not auriculate; roots thin; proximal petal blue to lilac or lavender, conspicuous; some locules usually 2-seeded. > 7
7 Perennials with erect to ascending stems; leaf sheaths with red hairs at summit; leaf blades 6–20 cm; spathes 1.5–3.5 cm; subterranean, cleistogamous flowers absent Commelina virginica
7 Annuals or perennials with ascending to decumbent, repent or scrambling stems; sheaths with or without red hairs at summit; leaf blades 1.5–7(–9) cm; spathes 0.5–2 cm; subterranean, cleistogamous flowers sometimes present. > 8
8 Leaf blades ovate to lanceolate-elliptic; sheaths often with red hairs at summit; lateral stamen filaments not winged; capsules usually 5-seeded Commelina benghalensis
8 Leaf blades oblong to lanceolate-oblong or oblong-elliptic; sheaths without red hairs; lateral stamen filaments winged; capsules usually 1-seeded Commelina forskaolii
... more about "Commelina"
Robert B. Faden +
Plumier ex Linnaeus +
petiolate +  and sessile +
succulent +
Dayflower +  and widow's-tears +
Almost worldwide +  and mainly tropical +
for the two Dutch botanists Jan and Kaspar Commelijn, because of the two showy petals +
thyrsiform +  and cymose +
arranged +  and 2-ranked +
cauline +  and basal +
not glaucous +
connate +  and distinct +
distinct +
unequal +
subequal +  and smaller +
brashier1966a +, faden1993a +  and pennell1916a +
distinct +
subequal +
staminodial +
some +  and fertile +
not +  and enlarged +
slender +
Commelina +
Commelinaceae +
annual +  and perennial +