Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
Onagraceae - The Evening Primrose Family
Perennial and annual herbs (those included here), often flowering in the first
year when perennial. Leaves simple, alternate, opposite or frequently
both on the same plant, entire or toothed, sessile or short-petioled, exstipulate.
Flowers solitary in the axils of leaves or leaflike bracts, sessile or
pedicelled, often arranged in distinct terminal inflorescences (bracteate spikes
or racemes), perfect, regular, 4-merous, epigynous, the sepals, petals and stamens
arising from the summit of the ovary or from the rim of a short floral tube
prolonged beyond the ovary; sepals free; petals free, white, yellow
or pinkish to rose-purple; stamens 8 or 4; stigma capitate or
often 4-lobed, style 1, ovary 4-celled, often 4-angled, sometimes long and slender
to appear like a pedicel or an extension thereof. Fruit a dehiscent,
4-valved capsule or sometimes weakly dehiscent; seeds many, with or without
a tuft of hairs (coma).
||Petals minute or absent, greenish when present;
seeds without a coma.
||Petals white, pinkish or rose-purple; seeds with
or without a coma.
||Plants annual; seeds without a coma.
||Genus Boisduvalia (B. glabella)
||Plants perennial, often flowering the first year;
seeds with a coma.
31. Onagraceae, the Evening Primrose Family
1. Boisduvalia Spach
2. Epilobium L. -- Willow herb
- 1. Boisduvalia glabella (Nutt.) Walp.
3. Ludwigia L. -- Seedbox
- 1. Epilobium ciliatum Raf.
- 2. Epilobium coloratum Biehler --
Purple-leaved willow herb
- 3. Epilobium leptophyllum Raf. --
Narrow-leaved willow herb
- 1. Ludwigia palustris (L.) Ell. --
- 2. Ludwigia polycarpa Short & Peter
-- Many-seed seedbox
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