Guayacan

Guaiacum angustifolium

Other common name(s):

Texas Lignum-vitae, Soapbush

Family:

Zygophyllaceae (Creosote Bush Family)

Plant Ecoregion Distribution Map

This map uses data from the US EPA. EPA  servers have been offline frequently so maps may not display. We are working on a solution.

Chihuahuan Deserts, Edwards Plateau, Gulf Coast Prairies and Marshes, Southern Texas Plains
Chihuahuan Basins and Playas, Chihuahuan Desert Grasslands, Chihuahuan Montane Woodlands, Low Mountains and Bajadas, Stockton Plateau
Balcones Canyonlands, Edwards Plateau Woodland, Llano Uplift, Semiarid Edwards Plateau
Southern Subhumid Gulf Coastal Prairies
Northern Nueces Alluvial Plains, Rio Grande Floodplain and Terraces, Semiarid Edwards Bajada, Texas-Tamaulipan Thornscrub

Plant Characteristics

Growth Form

Shrub

Height

8
to
10
ft.

Spread

15
to
20
ft.

Leaf Retention

Evergreen

Lifespan

Perennial

Habitat and Care Requirements

Soil Type(s)

Sand, Loam, Clay, Well Drained, Dry

Light Requirement

Sun, Part Shade

Water Requirement

Low

Native Habitat

Grassland

Bloom and Attraction

Bloom Color

Purple

Bloom Season

Spring, Summer

Seasonal Interest

Fruit, Nectar, Pollen, Larval Host, Nesting Material

Wildlife Benefit

Butterflies, Birds, Small Mammals, Nectar Insects, Bees

Maintenance

Low maintenance. Drought, heat, and cold tolerant. Grows faster with extra water. Showy, aromatic, long-living. Propagation: seed.

Comments

Blooms March-September. Develops one or more trunks that are smooth when mature. Pale blue to lilac flowers appear after a rain. Heart-shaped pods open at maturity and produce 2 scarlet-red, shiny seeds. The leaves are small and leathery; pinnately compound, and dark green. Larval host: Gray Hairstreak and Lyside Hairstreak.
Previous Scientific Name(s): Porlieria angustifolia

References

1) Griffith, Bryce, Omernick & Rodgers (2007). Ecoregions of Texas. 2) Wasowski and Wasowski, Native Texas Plants Landscaping Region by Region, 1991, pg. 290. 3) https://www.wildflower.org/plants/result.php?id_plant=GUAN. 4) http://bonap.net/TDC/Image/Map?taxonType=Species&taxonId=24172&locationType=County&mapType=Normal., 5) https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=38521#null

About the Region

Fall Symposium 2025 Logo - Teach for the Future

Salado, the location of our Fall 2025 Symposium, lies at the intersection of two ecoregions: the Edwards Plateau (Limestone Cut Plain) and Blackland Prairie (Northern Blackland Prairie).

The Edwards Plateau area is also called the Hill Country; however, this general term covers a much larger area extending farther north. Spring-fed creeks are found throughout the region; deep limestone canyons, rivers, and lakes (reservoirs) are common. Ashe juniper is perhaps the most common woody species found throughout the region. Additional woody species include various species of oak, with live oak (Quercus fusiformis) being the most common. Sycamores (Platanus occidentalis) and bald cypress (Taxodium distichum) border waterways. This area is well known for its spring wildflower displays, though they may be viewed in spring, late summer, and fall, as well. According to Texas Parks and Wildlife, average annual rainfall in the Edwards Plateau ranges from 15 to 34 inches.

The Blackland Prairie extends from the Red River south to San Antonio, bordered on the west by the Edwards Plateau and the Cross Timbers, and on the east by the Post Oak Savannah. Annual rainfall averages 30 to 40 inches, with higher averages to the east. This region is dominated by prairie species. The most common grass species include little bluestem (Schizachyrium scoparium) and Indian grass (Sorghastrum nutans) in the uplands and switchgrass (Panicum virgatum) in the riparian areas and drainages. Common herbaceous flowering plants include salvias, penstemons, and silphiums. This area has suffered greatly from overgrazing and agricultural use. Few intact areas remain, though many of the plants can be found along county roadsides throughout the region.

Our fall Symposium host chapter, the Tonkawa Chapter, includes both of these ecoregions.

Source: Wildflowers of Texas by Michael Eason