Evening-primroses

Seedbox Common Water-purslane Pink Evening-primrose Narrow-leaved Evening-primrose

What are they?

Evening-primroses are common plants of prairies and open grasslands throughout much of North America. Several species are grown as agricultural crops for their essential oils.

Where are they found?

Many species are common in open, often dry, grassy places, even semi-arid sites such as sand dunes. Others more typically grow in wetland areas such as damp fields and the edges of swampy ground. Some species have spread due to cultivation and are most often found as adventives on waste ground and along roadsides.

Identification

The four petals, usually widely separated at the base, and the usually often rather large flowers make evening-primroses as a group fairly straight forward to recognize. The identification of some evening-primroses at the species level is also relatively straight forward, but others can be quite tricky, especially those that have escaped from cultivation and may be hybrids (which are not uncommon in this group). Critical attention to the hairs on stems and developing seed pods can sometimes be necessary.



American Enchanter's-nightshade      Circaea canadensis

(Broad-leaved Enchanter's-nightshade) Local on leafy forest floors, usually forming colonies. Flowers June to August. Not officially recorded for Cape May County, but known from wet woodland at Higbee Beach WMA. This plant is placed here next to other, superficially similar-looking, members of the primrose family, though this plant is actually related to the evening-primroses and willowherbs.
American Enchanter's-nightshade American Enchanter's-nightshade American Enchanter's-nightshade American Enchanter's-nightshade
Habit
Flower
Leaf
Seed capsule

Purple-leaved Willowherb      Epilobium coloratum

Uncommon in wetlands and other damp areas. Flowers late July to early September. Flowers very pale pink, almost white, but darker in bud. In our area, the deeply-notched, pale petals on flowers carried on loose, open stems are distinctive.
Purple-leaved Willowherb Purple-leaved Willowherb Purple-leaved Willowherb Purple-leaved Willowherb
Habit
Flower
Leaf
Seed pod

Common Water-purslane      Ludwigia palustris

(Marsh Seed-box, Marsh Purslane) A common plant of wetlands and other swampy areas, though easily overlooked due to its small, petalless flowers. Flowers June to September. At first glance bears little resemblance to other members of its family due to the tiny flowers, carried in the axils of the opposite leaves. The flowers appear to have small, greenish petals but these are actually the sepals.
Common Water-purslane Common Water-purslane Common Water-purslane Common Water-purslane
Habit on mud
Habit in water
Flowers
Leaves

Globe-fruited Primrose-willow      Ludwigia sphaerocarpa

Local but often common where it occurs, in a seasonally flooded ponds and low, wet areas. Flowers July to September. When growing in standing water, the stems grow spongy growths around them and can become strangely disfigured.
Globe-fruited Primrose-willow Globe-fruited Primrose-willow Globe-fruited Primrose-willow Globe-fruited Primrose-willow
Habit
Flower
Leaf
Stem

Seedbox      Ludwigia alternifolia

Fairly common in wetlands and other swampy areas. Flowers late June to September. Flowers resemble those of the evening-primroses but the rest of the plant is quite different, with narrow, willowy leaves and thin, upright stems.
Seedbox Seedbox Seedbox Seedbox
Habit
Flower
Sepals persist after
flowering
Seed pod

Floating Primrose-willow      Ludwigia peploides

A south-eastern species that has the capacity to become invasive in wetlands, where it grows out into open water from shallow margins. First recorded in Cape May County in 2012. Flowers August to October.
Floating Primrose-willow Floating Primrose-willow Floating Primrose-willow Floating Primrose-willow
Habit
Flower
Leaves
Seed pod

Common Evening-primrose      Oenothera biennis

Common and widespread in all sorts of open ground, fields and roadsides, especially in dry spoil. Flowers June to October.
Common Evening-primrose Common Evening-primrose Common Evening-primrose Common Evening-primrose
Flower
Leaves
Seed pod
Close-up of
seed pod

Oakes's Evening-primrose      Oenothera oakesiana

Formerly considered a form of Common Evening-primrose and in New Jersey, currently only officially recorded from Cape May County. Several plants of this species flowered along the Main Trail at The Nature Conservancy's South Cape May Meadows in 2010. As this site received much disturbance and alteration in the years running up to this date, it is possible that this species was introduced to the site, perhaps on earth-moving equipment. Flowers June to October. In a local context, this species is relatively easy to identify as it superficially resembles Common Evening-primrose but has much smaller flowers. The leaves are slightly toothed and most of the plant bears silky white hairs.
Oakes's Evening-primrose Oakes's Evening-primrose Oakes's Evening-primrose Oakes's Evening-primrose
Flower
Leaf with slightly
wavy edges
Silky white hairs
on stem
Seed pod

Seaside Evening-primrose      Oenothera humifusa

Widespread and occasionally locally common on sandy beaches and dunes. Flowers July to September. Generally a low-growing species, with all parts thickly covered in silky hairs, giving it a pale, grayish look.
Seaside Evening-primrose Seaside Evening-primrose Seaside Evening-primrose Seaside Evening-primrose
Habit
Flower
Young leaves
in whorls
Whole plant covered
in silvery hairs

Cut-leaved Evening-primrose      Oenothera laciniata

Generally found growing as an adventive or weed of old fields, roadsides and waste ground and usually in dry soils. Flowers May to July.
Cut-leaved Evening-primrose Cut-leaved Evening-primrose Cut-leaved Evening-primrose Cut-leaved Evening-primrose
Flower from above
Flower from side
Deeply cut leaves
Leaves on young plants
often merely toothed

Narrow-leaved Evening-primrose      Oenothera fruticosa

(Narrow-leaved Sundrops) A showy plant with startlingly yellow flowers, typically found in swampy ground. Flowers June to August.
Narrow-leaved Evening-primrose Narrow-leaved Evening-primrose Narrow-leaved Evening-primrose
Habit
Close-up of
flower
Willow-like leaves

Pink Evening-primrose      Oenothera speciosa

Native to the central prairies of North America, this pink-flowered, annual species is widely grown as a garden plant and occasionally can be found self-seeded in urban areas on roadsides and uncultivated plots. Flowers June to August.
Pink Evening-primrose Pink Evening-primrose Pink Evening-primrose
Habit
Close-up of
flower
Leaves lobed
towards base

Lindheimer's Beeblossom      Oenothera lindheimeri

Native to Texas and the Gulf States, this annual species is widely grown as a garden plant and occasionally can be found self-seeded in urban areas on roadsides and uncultivated plots. Flowers July to October. The asymetrical, four-petaled flowers, carried on long, slender stems are distinctive. Cultivated forms also come in pink.
Lindheimer's Beeblossom Lindheimer's Beeblossom Lindheimer's Beeblossom Lindheimer's Beeblossom
Habit
Flower
Flower
Leaf