E-Flora BC: Electronic Atlas of the Flora of BC

Ammannia robusta Heer & Regel
scarlet ammannia (grand redstem)
Lythraceae (Loosestrife family)

Introduction to Vascular Plants

General:
Annual herb from spreading roots; stems erect to decumbent, solitary, simple or branched at the bases, 5-40 cm tall.

Leaves:
Basal leaves lacking; stem leaves usually opposite, unstalked, oblong-lanceolate, 2-4 cm long, 2-8 mm wide, heart-shaped and clasping at the base, glabrous.

Flowers:
Inflorescence of 2-5, rarely 1, urn-shaped flowers in compact axillary clusters; petals usually 4, purplish, 3-4 mm long; styles at least 1 mm long, slightly exserted from the 4-toothed calyx.

Fruits:
Capsules, membranous, nearly round, about 4 mm long.

Source: The Illustrated Flora of British Columbia

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

Origin Status	Provincial Status	BC List (Red Blue List)	COSEWIC
Native	S1	Red	E (May 2001)

BC Ministry of Environment: BC Species and Ecosystems Explorer.

Ammannia robusta shares habitat with Rotala ramosior and may be separated from it by its lavender to scarlet flowers (Washington Natural Heritage Program website, accessed March, 2005). Additionally, leaves of A. robusta are sessile and clasping at the base whereas leaves of R. ramosior gradually taper to a distinct petiole (Douglas 1995). Ammannia robusta has at least some leaf axils with three to five flowers, while R. ramosior rarely has more than one flower per leaf axil (Douglas 1995).

Source: British Columbia Conservation Data Centre

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