Rotala ramosior (L.) Koehne
toothcup meadow-foam (lowland rotala)
Lythraceae (Loosestrife family)
Introduction to Vascular Plants
toothcup meadow-foam (lowland rotala)
Lythraceae (Loosestrife family)
Introduction to Vascular Plants
Photograph
Species Information
General:
Annual herb from spreading roots; stems erect to decumbent, solitary, simple or branched at the bases, 5-15 cm tall.
Leaves:
Basal leaves lacking; stem leaves usually opposite, tapered to short stalks, glabrous, lanceolate to oblanceolate, 1.5-3 cm long, 2-7 mm wide.
Flowers:
Inflorescence of solitary, urn-shaped, axillary flowers, the flowers usually only 1 per axil; petals white, usually 4, about 1 mm long; styles less than 1 mm long, not exserted from the calyx.
Fruits:
Capsules, round, about 3 mm long.
Illustration
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
Habitat and Range
Wet, sandy lake shores and ponds in the steppe zone; rare in SC BC, known only from Osoyoos Lake and Kamloops Lake; disjunct to ON, S to NH, FL, CA and MX; W Indies.Status Information
| Origin Status | Provincial Status | BC List (Red Blue List) | COSEWIC |
|---|---|---|---|
| Native | S1 | Red | E (Nov 2014) |
BC Ministry of Environment: BC Species and Ecosystems Explorer.
Synonyms
Synonyms and Alternate Names:
Rotala catholica (Cham. & Schlecht.) van Leeuwen
Rotala dentifera (A. Gray) Koehne
Rotala ramosior var. interior Fern. & Grisc.
Rotala ramosior var. typica Fern. & Grisc.
Similar Species
This species shares its habitat with Ammania robusta, and may be separated from this genus by its white flowers. In Ammania species, flowers range from lavender to scarlet (Washington Natural Heritage Program 2005). Additionally, leaves of Ammania robusta are sessile and clasping at the base while leaves of Rotala ramosior gradually taper to a distinct petiole (Douglas and Oldham 1999). Ammannia robusta has at least some leaf axils with three to five flowers, while Rotala ramosior rarely has more than one flower per leaf axil (Douglas and Oldham 1999).
Source: British Columbia Conservation Data Centre |