Commelina erecta

What to Eat

Edible parts: Leaves, Root

Whitemouth dayflower: Not recommended as a food plant due to lack of confirmation. Birdbill dayflower (comparative reference): Roots excellent, leaves edible but sparse; high potential but limited documentation. This genus illustrates a key foraging principle: never assume edibility across a genus—species identity matters. Edible Uses & Rating: Whitemouth dayflower has no reliable documentation of edible use for leaves, flowers, or stems, and only the roots are occasionally mentioned as potentially edible. Because of this lack of confirmation, it should not be treated as a food plant. Birdbill dayflower, however, is a different case. Its roots are edible and of very high quality, and its leaves are mild and lettuce-like. This contrast suggests that edibility within the genus varies by species and that species-level identification is essential. Overall rating for whitemouth dayflower as a food plant: low / uncertain. Overall rating for birdbill dayflower (comparative reference): high potential (roots especially). Taste, Processing & Kitchen Notes: Whitemouth dayflower has no established culinary tradition, and taste data are not available in a reliable form. Birdbill dayflower roots, by contrast, are described as mild, potato-like, and versatile. They can be eaten raw or cooked and perform well in soups, boiling, baking, frying, and steaming, producing a sweet, hearty broth when simmered. Leaves of birdbill dayflower are mild, tender, and lettuce-like, though sparse in quantity, making them impractical for large harvests. This contrast highlights an important foraging principle: genus-level similarity does not guarantee species-level edibility. Seasonality (Phenology): Whitemouth dayflower typically blooms from late spring through summer, roughly May to September, depending on location and rainfall patterns. Birdbill dayflower in the Southwest blooms mainly during the summer monsoon season, from July to October. Roots can theoretically be harvested year-round, but aboveground growth is usually needed to locate the plants. Safety & Cautions (Food Use): Whitemouth dayflower should not be treated as an edible plant due to a lack of reliable documentation. Do not generalize edibility from eastern Commelina species or from birdbill dayflower to whitemouth dayflower. Species-level identification is essential. Birdbill dayflower roots appear safe based on field testing and related species, but documentation is limited, so cautious, minimal testing is always advised. Harvest & Processing Workflow: For whitemouth dayflower, no harvest workflow is recommended for food use. For birdbill dayflower (comparative reference), roots are located by identifying aboveground plants during the growing season, gently excavating clustered tuberous roots, leaving some behind for regeneration, and processing like small potatoes. Cultivar/Selection Notes: There are no food cultivars of whitemouth dayflower. Related species in Mexico and Central America are sometimes treated collectively, reflecting their similar root structures and uses, but this has not translated into formal agricultural selection in North America. Look-Alikes & Confusion Risks: Dayflowers can be confused with spiderworts (Tradescantia), but dayflowers are distinguished by hairless filaments and the presence of a large folded spathe (bird’s-bill-like bract). Within Commelina, correct species identification is critical because edibility varies significantly. Traditional / Indigenous Use Summary: Whitemouth dayflower does not have strong ethnobotanical documentation as a food plant. In contrast, related species in Mexico and the Southwest region show food use of roots, and birdbill dayflower appears to have real edible potential, though documentation remains sparse. This pattern suggests localized traditional knowledge rather than widespread cultural use. Root. Fleshy.

Known Hazards

Where to Find It

It is a warm temperate plant. In Argentina it grows below 700 m above sea level. It suits hardiness zones 6-9.

Africa, Argentina, Botswana, Brazil, Burkina Faso, Central America, Chile, Costa Rica, East Africa, Ethiopia, Guyana, Mozambique, Nicaragua, North America, Paraguay, South America, Southern Africa, Uruguay, USA, West Africa,

How to Identify

A herb. It keeps growing from year to year. The leaves are 4-15 cm long by 1-4 cm wide. The flowers are blue.

How to Grow

Whitemouth dayflower is best understood as a botanically interesting but nutritionally uncertain species. It belongs to a genus that includes excellent food plants, but it itself lacks reliable edible documentation. For foragers, it is more valuable as a learning species for identification and genus recognition than as a food source. Birdbill dayflower, however, stands out as a genuinely promising edible relative, especially for its roots. Growing Conditions: Whitemouth dayflower favors grasslands, open woodlands, and seasonally moist sites, often appearing in disturbed soils, field margins, and open habitats. It tolerates heat well and grows during warm months, behaving as a summer-active perennial. Birdbill dayflower prefers montane grasslands and woodland edges in southern Arizona and New Mexico, especially in areas influenced by summer rains. Habitat & Range: Whitemouth dayflower ranges from the southeastern United States westward into southeastern Arizona and northward into the central plains and mid-Atlantic regions. It is more common outside the core Southwest. Birdbill dayflower is primarily restricted to Arizona and New Mexico, occurring in mountain grasslands and woodlands. Size & Landscape Performance: Whitemouth dayflower is a small to medium herbaceous perennial that does not form dense groundcover. It persists through underground root systems and reappears seasonally. It is not aggressive or invasive in most natural systems. Cultivation (Horticulture): Dayflowers are sometimes grown ornamentally for their bright blue flowers, but whitemouth dayflower is not cultivated as a food plant. Birdbill dayflower and related tropical species (such as tuberous dayflower in Mexico) show that the genus has horticultural and food potential, but this has not been developed for North American cultivation. Pests & Problems: Some sources warn of saponins in roots and oxalates in leaves for certain Commelina species, though field sampling of birdbill dayflower did not show noticeable adverse effects. In general, insect damage and fungal issues can affect flowers and leaves, especially in humid conditions. Pollination: Flowers are insect-pollinated, with their bright blue petals attracting bees and other pollinators. The spathe structure protects developing flowers and seeds. Identification & Habit: Whitemouth dayflower is a perennial, joint-stemmed plant with a soft, grass-like appearance and leaves that resemble narrow lily or grass blades. The stems are segmented at the nodes, and the leaves sheath the stem at their bases. The plant produces distinctive, irregular blue flowers that emerge from a large, folded, leaf-like bract called a spathe (often described as a “bird’s bill”). This spathe is one of the easiest identification features of the genus Commelina. In whitemouth dayflower specifically, the spathe margins are fused at the base, and the flowers are tri-petaled with two blue petals and one smaller white petal, giving the plant its common name. The overall form is upright to loosely spreading, and plants often occur in scattered patches rather than dense colonies. Birdbill dayflower, the southwestern relative, has a similar growth form but differs in flower structure and spathe shape, and—critically for foragers—produces small, clustered, tuber-like roots. Prefers a light well-drained loam with added leafmold. Succeeds in an ordinary, reasonably moist soil in a sunny position with some shelter. A polymorphic plant. This species is not very winter hardy, the roots are best dug up in autumn and stored like dahlias in a cool frost free place and then planted out in spring. When grown in a light well-drained soil and mulched well, the roots usually survive the winter outdoors.

Propagation: Seed — sow in March in a greenhouse. Germination usually takes 4–5 weeks at 20°C. Prick seedlings into individual pots when large enough to handle and plant out in late spring or early summer after the last expected frosts. Division in early spring, ensuring each portion has at least one growing bud. Cuttings taken during the growing season root very easily.

Medicinal Uses

None known

Other Uses

Dayflowers are sometimes grown ornamentally for their bright blue flowers. They provide nectar and pollen for insects and contribute to warm-season floral diversity. Their low, soft growth provides microhabitat for insects and small invertebrates. In natural systems they function as ecological background species rather than dominant plants.

Commelina erecta, commonly known as white mouth dayflower, slender dayflower, or widow's tears. C. erecta is a blue flower often recognized by its two large blue petals and smaller white petal. It is a perennial herb common across the world and native throughout the Americas, Africa and western Asia.

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