Xanthisma texanum aka Texas Sleepy Daisy
Taxonomy ID: 14329
Xanthisma texanum, commonly known as the Texas Sleepy Daisy or Star of Texas, is an attractive annual wildflower native to the prairies of the southwestern United States and northern Mexico. This member of the Asteraceae family is the sole representative of Xanthisma sect. Xanthisma and has been cultivated as an ornamental since its discovery in the 1830s.
The plant features slender, wand-like stems that typically grow 1-3 feet (30-90 cm) tall, forming a bushy, spreading mound. The stems are lined with long, narrow, glossy green leaves that are alternately arranged. Lower leaves are larger (1-2.5 inches) and often deeply lobed or toothed, while upper leaves are smaller and rarely toothed. The foliage creates an attractive ferny appearance throughout the growing season.
The most distinctive characteristic of Xanthisma texanum is its unique flowering behavior—the bright lemon-yellow, daisy-like flowers don't open until around noon, remaining closed during morning hours, which gives rise to its common name "sleepy daisy." The solitary, terminal flower heads are 1.5-2 inches across with long, slender yellow ray florets surrounding a central yellow disc. This afternoon-blooming habit makes it a charming addition to gardens where it puts on its show during the hottest part of the day.
Xanthisma texanum blooms prolifically from April through December, providing an exceptionally long flowering season. The plant produces cypselae (small dry fruits) that readily self-seed. This species has notable cytological interest in botanical research due to its low chromosome count (2n=8) and the presence of B chromosomes that have been studied extensively.
In its native habitat, the Texas Sleepy Daisy grows in dry, open rangelands, stream banks, prairies, plains, meadows, and savannas. It thrives in sandy plains, granite soils, roadsides, shortgrass prairies, and sage scrub at elevations of 2,500-4,300 feet. The plant has proven adaptable and has escaped cultivation in areas far outside its natural range, including Northern California and even North Africa.
Common names
Texas Sleepy Daisy, Sleepy Daisy, Texas SleepydaisyMore information about Texas Sleepy Daisy
How easy is it to grow Xanthisma texanum?
Xanthisma texanum is an easy-to-grow annual that requires minimal maintenance once established. It is highly drought tolerant, heat tolerant, and adapts to various soil conditions including poor soils. The plant is pest-resistant with aphids being the only occasional concern.
How often should I water Xanthisma texanum?
Xanthisma texanum is drought tolerant once established and requires infrequent watering. In its native prairie habitat, it thrives on natural rainfall. During establishment, provide water to initiate germination, but once the plant is growing, allow soil to dry between waterings. Avoid overwatering as this can lead to root rot.
What type of soil does Xanthisma texanum need?
Xanthisma texanum is highly adaptable to various soil types including sand, loam, clay, and caliche. It prefers circumneutral pH (6.5-7.2) and performs well even in poor soils. Good drainage is important, but the plant tolerates a range of conditions from sandy plains to granite soils. Native American Seed rates its ground stability at 3- on their scale.
What light does Xanthisma texanum require?
Xanthisma texanum thrives in full sun, which is essential for optimal growth and abundant flowering. While it can tolerate part shade, full sunlight produces the best results with more vigorous growth and more prolific blooms. This native prairie wildflower evolved in open, sunny habitats and performs best when given similar conditions.
How do I propagate Xanthisma texanum?
Xanthisma texanum is propagated by seed. Sow seeds outdoors after the last frost, lightly covering them with soil and spacing 6-24 inches apart. For earlier blooms, start seeds indoors 7 weeks before the last frost and transplant after frost danger has passed. Seeds germinate in 3-4 weeks at temperatures of 68-73°F (20-23°C). Seeds sown in late winter or early spring require moisture to initiate germination.
How big does Xanthisma texanum grow?
Xanthisma texanum typically grows 1-3 feet (30-90 cm) tall and spreads to form a bushy, ferny mound of similar width. The plant develops slender, wand-like stems from a fibrous root system. Growth habit is compact and spreading, making it suitable for borders, pocket prairies, and wildflower meadows. As an annual, it completes its full lifecycle within a single growing season.
When and how does Xanthisma texanum flower?
Xanthisma texanum produces bright lemon-yellow, daisy-like flowers that are 1.5-2 inches across. The most distinctive feature is that flowers don't open until around noon, remaining closed during morning hours—hence the common name 'sleepy daisy.' The exceptionally long bloom period extends from April through December. Deadheading spent flowers encourages continued blooming throughout the season.
Where is Xanthisma texanum native to?
Xanthisma texanum is native to the southwestern United States and northern Mexico. Its range includes Oklahoma and the western two-thirds of Texas, extending west through New Mexico to southeastern Arizona, and south into Mexico. Native habitats include dry, open rangelands, stream banks, prairies, plains, meadows, pastures, savannas, and sage scrub at elevations of 2,500-4,300 feet.
Can Xanthisma texanum grow outdoors year-round?
Xanthisma texanum is exclusively an outdoor plant, hardy in USDA zones 3-8. As a native prairie wildflower, it is well-suited to outdoor cultivation in gardens, meadows, and naturalized areas. It excels in pocket prairies, rock gardens, rocky hillsides, and wildflower meadows. The plant is highly heat tolerant and deer resistant, making it excellent for challenging outdoor locations.
What temperatures does Xanthisma texanum prefer?
Xanthisma texanum is highly heat tolerant, thriving in the hot summers of its native Texas prairies. Seeds germinate best at 68-73°F (20-23°C). The plant performs well through hot afternoons—in fact, its flowers only open during the warmest part of the day. It is frost-tender as an annual and should be planted after the last frost in spring.
What varieties of Xanthisma texanum exist?
Xanthisma texanum includes three recognized varieties: var. drummondii (Drummond's Sleepy-daisy), var. texanum, and var. orientale. Varieties texanum and orientale are found in southern Texas where they occasionally hybridize, while var. drummondii is more widely distributed from Oklahoma through Texas, New Mexico, and into Arizona. The species is classified into two subspecies: ssp. drummondii and ssp. texanum (containing var. texanum and var. orientale).
Does Xanthisma texanum need pruning?
Xanthisma texanum benefits from deadheading spent flowers to extend the blooming period throughout its long April-December flowering season. Taller specimens may benefit from staking for support. As an annual that completes its lifecycle in one season, no other pruning is typically necessary. Allow some flowers to go to seed if you want the plant to self-sow for the following year.
What pests and diseases affect Xanthisma texanum?
Xanthisma texanum is notably pest-resistant and generally trouble-free. Aphids are the only common pest concern, which can be managed with a strong spray of water or insecticidal soap if populations become problematic. Overwatering can lead to root rot, so ensure good drainage and allow soil to dry between waterings. The plant's native prairie origins make it well-adapted to challenging conditions.
How is Xanthisma texanum pollinated?
Xanthisma texanum is pollinated by insects, particularly bees. As a member of the Asteraceae family with yellow daisy-like flowers, it attracts native pollinators that are essential to Texas ecosystems. Texas hosts over 700 native bee species that pollinate native plants like this one. The afternoon-opening flowers provide nectar and pollen during the warmest part of the day when many pollinators are most active.
