Calylophus serrulatus (Yellow Sundrops)

Plant Info
Also known as: Toothed Evening Primrose, Plains Yellow Primrose
Genus:Calylophus
Family:Onagraceae (Evening Primrose)
Life cycle:perennial
Origin:native
Habitat:sun; dry prairies
Bloom season:June - August
Plant height:1 to 2 feet
Wetland Indicator Status:none
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information

Flower: Flower shape: 4-petals

[photo of flower] Single yellow flowers in the upper leaf axils, ½ to 1 inch across, with 4 rounded petals, often quite wrinkled like crumpled tissue paper, with wavy edges that are sometimes a bit ragged, and a rounded notch at the tip. In the center are 8 yellow stamens surrounding a stigma with 4 disc-shaped lobes. The 4 sepals are less than ¼ inch long, triangular to egg-shaped with a prominent mid-rib, and reflexed down at bloom time. Flowers are stalkless but sit on top of a hairy, cylindrical ovary about 3/8 inch long that resembles a stalk.

Leaves and stems: Leaf attachment: alternate Leaf type: simple

[photo of leaves] Leaves are narrowly oblong, linear, or widest above the middle, 1 to 3 inches long and not more than ¼ inch wide, stalkless, may be toothless but usually with small, sharp teeth around the edges and short hairy on the underside. Stems are erect, green to brown, covered in stiff, fine hairs, often clustered from a root crown but not much branched, and woody in the lower stem.

Fruit: Fruit type: capsule/pod

[photo of fruit] Fruit is a slender, cylindrical capsule in the leaf axils, slightly tapered at both ends, ½ to 1¼ inches long, covered with fine, short hairs.

Notes:

At first glance, Calylophus serrulatus looks like an Oenothera and not surprisingly, at one time it was known as Oenothera serrulata. Common in dry prairies, it is typically much shorter than the tall spiked stems of other common evening primroses and has much narrower leaves. A distinction with this species is that it blooms during the day where Oenothera flowers open in afternoon or evening, for pollination by night-flying insects.

Please visit our sponsors

  • Minnesota Native Plant Society

Where to buy native seed and plants ↓

Map of native plant purveyors in the upper midwest

  • Prairie Restorations - Bringing people together with the land
  • Shop for native seeds and plants at PrairieMoon.com!
  • Shooting Star Native Seeds - Native Prairie Grass and Wildflower Seeds
  • Morning Sky Greenery - Native Prairie Plants
  • Minnesota Native Landscapes - Your Ecological Problem Solvers

More photos

Photos by K. Chayka taken at Long Lake Regional Park, Ramsey County, and at Grey Cloud Dunes SNA, Washington County. Photos courtesy Peter M. Dziuk taken in Dakota and Pope counties.

Comments

Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: Nancy - Dakota and Goodhue Counties
on: 2013-08-01 10:13:50

I see this plant in remnant sand prairies and have found it in several locations. A beautiful but somewhat inconspicuous member of our native prairie flora!

Post a comment

Note: All comments are moderated before posting to keep the riff-raff out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.



(required)




Note: Comments or information about plants outside of Minnesota and neighboring states may not be posted because Id like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.