7. Commelina L., Sp. Pl. 1: 40 (1753).
Taxon Description
Annual or perennial herbs. Roots thin or tuberous. Rhizomes absent. Stems erect, slender and creeping below. Leaves spiral to alternate, lanceolate, base oblique, apex acuminate, glabrous to pubescent, sheaths vaginate, open, margin entire or slightly wavy. Inflorescence terminal, 1 or cymes enclosed in spathe, upper cyme single flowered, lower cymes several flowered, involucral bracts ovate, boat-shaped or spathe-like, not penetrating the leaf sheaths and emerges through the mouth of sheath, apex often acute or rounded. Flowers bisexual, zygomorphic. Pedicels present. Sepals 3, ovate, membranous. Petals 3, clawed, faintly blue. Stamens 6, staminodes 0–3, filaments glabrous or hairy, antherodes 4-lobed, longitudinally dehiscent. Ovary 2- or 3-loculed, ovules 1 per locule. Capsule 2- or 3-valved, oblong-elliptic to ovoid. Seeds 1 or 2 per valve, cylindric, trigonous, rugose, reticulate, hilum linear.
Taxon Statistics
Key to Species
1a Spathe funnelform; inflorescence terminal cyme .………………………………………………………………………………………………………………….………. 2
b Spathe conduplicate; inflorescence terminal cyme or distal ……………………………………………………………..………………………….………………… 5
2a Leaves petiolate. Seeds 2 per valve …..………………………………………………………………………..…………………………….……..… 1. C. benghalensis
b Leaves sessile. Seeds 1 per valve ………….……………………………………………………………………………………………………………….…………………..…… 3
3a Capsule 2-valved. Seeds oblong ………………………………………………………………………………………………………………….…..………… 2. C. undulata
b Capsule 3-valved. Seeds ellipsoid ……………..………………………………………………………………………………………………………………..……………..…… 4
4a Plants robust, 45–60 cm, stem erect . ………………………………………………………….……………………………..………….………..……..… 3. C. paludosa
b Plants to 30 cm, stem creeping .…..……………………………………………………………………………………………….……….……..…..…….… 4. C. maculata
5a Capsule 2-valved. Seeds smooth …………… …………………………………………………………………………………………..….………….…………………………. 6
b Capsule 3-valved. Seeds reticulate ………………………………………………………………………………………………………………………………. 5. C. diffusa
6a Annual herbs. Involucral bract spathaceous. Capsule oblong ………..……………………………………..………………………….…….6. C. caroliniana
b Perennial herbs. Involucral bract cordate. Capsule globose ……………………………………………………………………………….. 7. C. suffruticosa
1. Commelina benghalensis L., Sp. Pl. 1: 41 (1753).
Perennial herbs, 20–36 cm. Rhizomes absent. Stems slender and creeping below. Leaves spirally arranged, ovate, 3–6 X 1.5–4 cm, base oblique, apex acute, sheath with reddish-brown hairs. Inflorescence terminal, 1 or cymes enclosed in funnel-shaped spathe, upper cymes staminate, lower cymes several-flowered. Pedicels present. Flowers perfect and staminate, cleistogamous flowers at base, involucral bracts typically ovate to oblong, spathe-like and boat-shaped. Sepals 3, 3–4 mm, usually elliptic to ovate, apex slightly pointed or rounded, basal portion often narrowed, membranous. Petals 3, 0.4–1.2 cm, upper two broadly ovate to orbicular, lower petal typically spatulate or linear-oblong, faintly blue, longer, one clawed. Stamens 6, 4–6 mm, staminodes 3, blue. Ovary 3-loculed, ovules 1 per locule. Capsules 3-valved, oblong-elliptic. Seeds 1 per valve, black, cylindric or semicylindric, 1–2 mm, rugose, irregularly reticulate.
Distribution: Nepal, W. Himalaya, E. Himalaya, Assam-Burma, E. Asia, SE Asia, SW Asia, and Africa.
Altitudinal range: 100–1800 m.
Ecology: Common on moist and shady place.
Flowering: June– August.
Fruiting: August –September
2. Commelina undulata R.Br., Prodr. Fl. Nov. Holland.: 270 (1810).
Commelina kurzii C.B.Clarke; C. striata Edgew.
Perennial herbs, 16–20 cm. Roots thin. Stems diffuse, numerous branched, hirsute. Leaves sessile, lanceolate, apex acuminate, 4–8 X 1.5–2.5 cm, sheath ciliate, glabrous. Inflorescence terminal, involucral bracts 2–4, sessile, funnel form, 1.5–2 cm, hirsute, spathe-like, apex shortly falcate-acuminate. Pedicellate, pedicels twisting. Flowers zygomorphic. Sepals 3, 3–4 mm, ovate or elliptic, green, membranous. Petals 3, 0.8–1 cm, upper two broadly ovate or elliptic, pinkish blue, lower single, small, narrowly ovate or lanceolate, white or pale-coloured. Stamens 3, fertile, staminodes 3, antherode cruciform, blue. Ovary 2 loculed, ovules 1 per locule. Capsule 2-valved, sub-globose. Seeds 1 per valve, oblong, 1.6–4.2 mm, brown-black.
Distribution: Nepal, W. Himalaya, E. Asia, SE Asia; and Australasia.
Altitudinal range: 1500– 2500 m.
Ecology: Found in rocks
Flowering: July– August.
Fruiting: November–December.
3. Commelina paludosa Blume, Enum. Pl. Javae 1: 2 (1827).
Commelina obliqua Buch.-Ham. ex D.Don.
Perennial herbs, 45–60 cm. Rhizomes absent. Stems erect, branched, glabrous. Leaves alternate, lanceolate, 3.5–13.5 X 1–3 cm, sessile, sheath dense reddish brown, hirsute-ciliate, leaf blade ovate to lanceolate, usually glabrous sometimes hairy adaxially and hirsute abaxially. Inflorescence terminal cyme, cincinnus 1, spathe funnel form, smooth, involucral bracts, spathaceous, 4–10 cm, sessile, glabrous. Pedicels present. Flowers 1 to several, pedicellate. Sepals 3, 2–3 mm, ovate to elliptic, membranous, free. Petals 3, 0.3–1 cm, upper two broadly ovate to orbicular, vivid blue, lower small, narrowly ovate to lanceolate, often pale or light blue, free. Stamens 6, 4–6 mm, fertile filiform, slender, anthers bilobed, staminodes flattened, curved or spatulate, blue. Ovary 3 loculed, ovules 1 per locule. Capsules 3-valved, ovoid-globose. Seeds 1 per valve, ellipsoid, 1.4–3.6 mm, finely reticulate, dark brown.
Distribution: Nepal, W. Himalaya, E. Himalaya, Tibetan Plateau, Assam-Burma, E. Asia and SE Asia.
Altitudinal range: 150–3500 m.
Ecology: In moist, shady forest margin.
Flowering: August–September.
Fruiting: September–October.
4. Commelina maculata Edgew., Trans. Linn. Soc. London 20: 89 (1846).
Commelina obliqua var. viscida C.B.Clarke; C. paludosa var. viscida (C.B.Clarke) R.S.Rao & Kammathy.
Perennial herbs, 9–29 cm. Roots thin to tuberous. Stems creeping proximally, branched, slender, glabrous. Leaves alternate, ovate-lanceolate or lanceolate, 3–7.5 X 1–1.7 cm, sheaths brown ciliate at mouth, oily surface to glabrous. Inflorescence terminal cyme, cincinni 2-several flowers, spathe funnel form, pedicellate, hairy, involucral bracts spathe-like, 1.5–2 cm, apex acute. Pedicels present. Flowers zygomorphic. Sepals 3, 3–5 mm, elliptic to ovate, slightly pointed apex, membranous. Petals 3, 0.6–1 cm, upper two larger, broadly ovate to orbicular, typically bright blue, lower single, narrowly ovate to lanceolate, often white or faint blue. Stamens 3-6, 4–6 mm, filiform, slender, filaments hairy, staminodes spatulate, flattened, curved, blue. Ovary 2-3 loculed, ovules 1 per locule. Capsules 3-valved, globose. Seed 1 per valve, ellipsoid, 1.2–3.2 mm, flattened, smooth, gray-black.
Distribution: Nepal, W. Himalaya, E. Himalaya, Tibetan Plateau, Assam-Burma, E Asia and SE Asia.
Altitudinal range: 700–1900 m.
Ecology: Found in moist places.
Flowering: June–July.
Fruiting: August– September.
5. Commelina diffusa Burm.f., Fl. Ind. (N.L. Burman): 18 Fig.2 Pl.7 (1768).
Commelina communis Walter.
Annual herbs, 30–40 cm. Rhizomes absent. Stems creeping, branched, glabrous. Leaves sub sessile, leaf sheath hispid, linear-lanceolate, 3–7.5 X 1–1.5 cm, base rounded, apex acuminate, glabrous. Inflorescence terminal cyme, cincinni branched, spathe conduplicate, pedicels thick, curved, involucral bract lanceolate, funnel form, proximal margin open or folded, not connate basally, base cordate or rounded, 1–4 cm. Pedicels present. Flowers zygomorphic. Sepals 3, 3–4 mm, ovate to elliptic, small, free, membranous. Petals 3, 4–7 mm, upper two longer, often ovate broadly, vivid blue, lower one single, small, usually pale whitish, conclorous. Stamens 6, 4–6 mm, 3 fertile, filiform, slender, staminodes 3, sterile, spatulate, flattened, blue. Ovary 3 loculed, ovules 1 per locule. Capsules 3-valved, oblong, trigonous. Seeds 1 per valve, ovoid-globose, 1.2–2.2 mm, reticulate, black.
Distribution: Nepal, W. Himalaya, E. Himalaya, Tibetan Plateau, Assam-Burma, S. Asia, E Asia, SE Asia, SW Asia; and Africa.
Altitudinal range: 100–1600 m.
Ecology: Diffusely spreading in margins of rice fields and wet places.
Flowering: May–November.
Fruiting: September–October.
6. Commelina caroliniana Walter, Fl. Carol.: 68 (1788).
Commelina hasskarlii C.B.Clarke.
Annual herbs, 20–70 cm. Rhizomes absent. Stems diffusely branched, decumbent. Leaves alternate, lanceolate, 3.5–7 X 1–1.4 cm, apex acute to acuminate, glabrous. Inflorescence distal cyme, spathe conduplicate, solitary, involucral bracts spathaceous, basal, subtending the flowers. Pedicels present. Flowers zygomorphic. Sepals 3, 2–4 mm, elliptic to ovate, free, membranous, green. Petals 3, 0.4–1 cm, upper two orbicular, blue, lower one ovate or lanceolate, transparent, small, pale blue or white, free. Stamens 6, 5–7 mm, with white connective, antherodes bilobed, cruciform, yellow. Ovary 3 loculed, ovules 1 per locule. Capsules 2-valved, oblong. Seeds 1 per valve, 1.1–2.8 mm, smooth to faintly alveolate, dark brown.
Distribution: Nepal, W. Himalaya, E Himalaya and Assam-Burma.
Altitudinal range: 100–1600 m.
Ecology: On wet fields.
Flowering: June– August.
Fruiting: August – September.
7. Commelina suffruticosa Blume, Cat. Gew. Buitenzorg: 35 (1823).
Commelina rugulosa C.B.Clarke; Spathodithyros suffruticosus (Blume) Hassk.
Perennial herbs, 20–36 cm. Roots tuberous. Stems erect, branched, glabrous. Leaves alternate, lanceolate to ovate-lanceolate, 3.5–13.5 X 1–3 cm, sheaths ciliate. Inflorescence terminal cyme, cincinni 4-flowered, spathe conduplicate, pedicellate, involucral bract cordate, obtuse at apex, open, 1.6 X 1.1 cm when twisted, rarely hirsute. Pedicels present. Flowers zygomorphic. Sepals 3, 3–5 mm, ovate to elliptic, membranous. Petals 3, 4–6 mm, upper two broadly ovate or elliptic, lower single, narrowly lanceolate or ovate, usually white, purple. Stamens 6, staminodes 3, blue. Ovary 3 loculed, ovules 1 per locule. Capsules 2-valved, globose. Seeds 1 per valve, ellipsoid, 2.2–3.4 mm, rugose, light brown.
Distribution: Nepal, E. Himalaya, Assam-Burma, E. Asia and SE Asia.
Altitudinal range: 100–200 m.
Ecology: Dominant inside the forest.
Flowering: August–September.
Fruiting: September–October.