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Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

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Calylophus hartwegii (Hartweg's sundrops)
Bransford, W.D. and Dolphia

Calylophus hartwegii

Calylophus hartwegii (Benth.) P.H. Raven

Hartweg's Sundrops, Western Primrose

Onagraceae (Evening Primrose Family)


USDA Symbol: CAHA14

USDA Native Status: L48 (N)


From the Image Gallery

12 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Leaf Retention: Deciduous
Fruit Type: Capsule
Size Notes: Up to about 2 feet tall, often shorter.

Bloom Information

Bloom Color: Yellow
Bloom Time: Mar , Apr , May , Jun , Jul , Aug , Sep , Oct , Nov


USA: AZ , CO , KS , NM , OK , TX
Native Habitat: Prairie, Plains, Meadows, Pastures, Savannas

Growing Conditions

Water Use: Low
Light Requirement: Part Shade
Soil Moisture: Dry
Soil Description: Clay, Clay Loam, Medium Loam, Sandy Loam, Sandy, Limestone-based, Gypseous, Caliche type
Conditions Comments: Somewhat upright and bushy plant with narrow leaves and soft yellow cup flowers that open in the evening and close the next afternoon shortly before new flowers open. This plant prefers fast draining soil and loves reflected heat making it an excellent choice for a rock garden or rocky slope. Deadheading and giving it some summer water will prolong the flowers. Cut back to 6-8" in the autumn to reshape.


Use Ornamental: Perennial garden, Color, Blooms ornamental, Rock gardens, Showy, Attractive
Conspicuous Flowers: yes
Nectar Source: yes


Propagation Material: Seeds


Bibref 318 - Native Texas Plants: Landscaping Region by Region (2002) Wasowski, S. & A. Wasowski
Bibref 286 - Wildflowers of the Texas Hill Country (1989) Enquist, M.

Search More Titles in Bibliography

Web Reference

Webref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

Additional resources

USDA: Find Calylophus hartwegii in USDA Plants
FNA: Find Calylophus hartwegii in the Flora of North America (if available)
Google: Search Google for Calylophus hartwegii


Record Modified: 2023-01-26
Research By: DEW, JSC

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