Calylophus hartwegii (Benth.) P.H. Raven
Hartweg's Sundrops, Western Primrose
Onagraceae (Evening Primrose Family)
USDA Symbol: CAHA14
From the Image Gallery
Plant CharacteristicsDuration: Perennial
Leaf Retention: Deciduous
Fruit Type: Capsule
Size Notes: Up to about 2 feet tall, often shorter.
Bloom InformationBloom Color: Yellow
Bloom Time: Mar , Apr , May , Jun , Jul , Aug , Sep , Oct , Nov
DistributionUSA: AZ , CO , KS , NM , OK , TX
Native Habitat: Prairie, Plains, Meadows, Pastures, Savannas
Growing ConditionsWater 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.
BenefitUse Ornamental: Perennial garden, Color, Blooms ornamental, Rock gardens, Showy, Attractive
Conspicuous Flowers: yes
Nectar Source: yes
PropagationPropagation Material: Seeds
BibliographyBibref 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 ReferenceWebref 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 resourcesUSDA: Find Calylophus hartwegii in USDA Plants
FNA: Find Calylophus hartwegii in the Flora of North America (if available)
Google: Search Google for Calylophus hartwegii
MetadataRecord Modified: 2023-01-26
Research By: DEW, JSC