Photo by Melody

PlantFiles: Drummond’s Sundrops, Square-Bud Primrose, Compact Gold Calylophus
Calylophus drummondianus

Family: Onagraceae (on-uh-GRAY-see-ee) (Info)
Genus: Calylophus (kal-ee-LOW-fus) (Info)
Species: drummondianus (drum-mond-ee-AH-nus) (Info)

4 members have or want this plant for trade.


12-18 in. (30-45 cm)

12-15 in. (30-38 cm)
15-18 in. (38-45 cm)

USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)
USDA Zone 10a: to -1.1 °C (30 °F)
USDA Zone 10b: to 1.7 °C (35 °F)

Sun Exposure:
Full Sun

Unknown - Tell us

Bloom Color:
Bright Yellow

Bloom Time:
Late Winter/Early Spring
Mid Spring
Late Spring/Early Summer
Mid Summer
Late Summer/Early Fall
Mid Fall


Other details:
This plant is attractive to bees, butterflies and/or birds
Drought-tolerant; suitable for xeriscaping

Soil pH requirements:
6.1 to 6.5 (mildly acidic)

Patent Information:
Unknown - Tell us

Propagation Methods:
From seed; direct sow outdoors in fall

Seed Collecting:
Allow pods to dry on plant; break open to collect seeds

Click thumbnail
to view:

By htop
Thumbnail #1 of Calylophus drummondianus by htop

By sweezel
Thumbnail #2 of Calylophus drummondianus by sweezel

By TxTurqoize
Thumbnail #3 of Calylophus drummondianus by TxTurqoize

By Kell
Thumbnail #4 of Calylophus drummondianus by Kell

By Kell
Thumbnail #5 of Calylophus drummondianus by Kell

By Kell
Thumbnail #6 of Calylophus drummondianus by Kell

By Kell
Thumbnail #7 of Calylophus drummondianus by Kell

There are a total of 13 photos.
Click here to view them all!


3 positives
1 neutral
No negatives

Gardeners' Notes:

Neutral frostweed On Mar 1, 2007, frostweed from Josephine, Arlington, TX (Zone 8a) wrote:

Drummond’s Sundrops, Square-Bud Primrose, Compact Gold Calylophus Calylophus drummondianus is native to Texas ans other States.

Positive LindaTX8 On Jan 14, 2006, LindaTX8 from NE Medina Co., TX (Zone 8a) wrote:

The Squarebud Primrose is a native wildflower in Texas. It grows here in my area along the roadsides, very pretty when blooming. I have the kind of this plant that have yellow flowers and black throat and stigma. They're gorgeous in spring, summer and fall. I let them self-sow to make new plants or collect seeds to move them to new areas. One of my absolute most favorite flowers! Although the info given above suggests acidic soil, it does well in alkaline soil, probably preferring it.

Positive kbrehm On May 22, 2004, kbrehm from Red Bluff, CA wrote:

Red Bluff, CA

I am growing this plant in a raised bed, in full sun, which receives water everyday. I planted two plants late last fall and both plants have exceeded my expectations in both size and showiness. They have spread two feet each and are covered with blooms. They remained evergreen over the winter.

Positive htop On Sep 20, 2003, htop from San Antonio, TX (Zone 8b) wrote:

San Antonio, TX
A native New Mexico and Texas plant, Drummond’s sundrops is a spreading ground cover closely related to the evening primrose. From March until November, it is covered in clusters with 2 inch wide bright yellow flowers which, when mature, turn to orange. Preferring full sun (it will take light shade with loss of some flowering), it attains a mound that is 1 to 1.5 feet tall and 1.5 feet wide. Not picky about soil types and highly drought tolerant, it is ideal for rock gardens and along walls. No plant is showier per square foot of bloom. After its first flowering, a light trimming will assist in maintaining a neat, compact habit and encourage further flower production. It is a relatively carefree plant which provides months of beauty.


This plant has been said to grow in the following regions:

Chandler, Arizona
Green Valley, Arizona
Benicia, California
Chico, California
Red Bluff, California
San Leandro, California
Boise, Idaho
Austin, Texas
Crawford, Texas
Fort Worth, Texas
Georgetown, Texas
Helotes, Texas
Rowlett, Texas
San Antonio, Texas (2 reports)

We recommend Firefox
Overwhelmed? There's a lot to see here. Try starting at our homepage.

[ Home | About | Advertise | Media Kit | Mission | Featured Companies | Submit an Article | Terms of Use | Tour | Rules | Privacy Policy | Contact Us ]

Back to the top

Copyright © 2000-2015 Dave's Garden, an Internet Brands company. All Rights Reserved.

Hope for America