Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
30. Lythraceae, the Loosestrife Family
1. Ammannia L. -- Toothcup
1. Ammannia auriculata Willd.
Slender annual 0.5-5(8) dm tall, simple or branched above the base, the branches
ascending. Leaves linear-lanceolate to linear-oblong, 1-4(6.5) cm long,
1.5-6(10) mm wide, auriculate-clasping at the base. Inflorescences of
simple to compound, rather open cymes, peduncled from the axils, with (1)3-12(15)
flowers per axil, most with at least 7 flowers; peduncles filiform, 3-9
mm long; pedicels 1-3(6) mm long. Calyx tube 1-3 mm long in flower,
the lobes alternating with short appendages or the appendages absent;
petals 4, deep rose-purple, ca. 1.5 mm long; stamens 4(-8), anthers
deep yellow when fresh; styles 1-3 mm long in fruit. Capsules
1.5-3 mm in diameter, equaling or exceeding the calyx. Jul--Oct. Muddy shores,
flats and low spots in fields where water stands temporarily; uncommon, ec SD
and s NE; (IN to SD, s to TX and into Mex., C. and S.Amer.; Old World tropics).
Return to Family -- Lythraceae - The
Next Species -- Ammannia coccinea Rottb.