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Zizotes Milkweed

Asclepias oenotheroides

Other common name(s):

Hierba de Zizotes

Family:

Apocynaceae (Dogbane Family)

Plant Ecoregion Distribution Map

Chihuahuan Deserts, East Central Texas Plains, Edwards Plateau, Gulf Coast Prairies and Marshes, Southern Texas Plains, Texas Blackland Prairies
Chihuahuan Basins and Playas, Chihuahuan Desert Grasslands, Chihuahuan Montane Woodlands, Low Mountains and Bajadas, Stockton Plateau
Bastrop Lost Pines, San Antonio Prairie, Southern Post Oak Savanna
Balcones Canyonlands, Edwards Plateau Woodland, Semiarid Edwards Plateau
Coastal Sand Plain, Lower Rio Grande Alluvial Floodplain, Lower Rio Grande Valley, Northern Humid Gulf Coastal Prairies, Southern Subhumid Gulf Coastal Prairies
Semiarid Edwards Bajada, Texas-Tamaulipan Thornscrub
Floodplains and Low Terraces1, Northern Blackland Prairie, Southern Blackland Prairie

Plant Characteristics

Growth Form

Herbaceous

Height

1
to
3
ft.

Spread

1
to
3
ft.

Leaf Retention

Deciduous

Lifespan

Perennial

Habitat and Care Requirements

Soil Type(s)

Sand, Gravelly, Limestone

Light Requirement

Sun

Water Requirement

Low

Native Habitat

Grassland

Bloom and Attraction

Bloom Color

Green

Bloom Season

Spring, Summer

Seasonal Interest

Nectar, Pollen, Larval Host

Wildlife Benefit

Butterflies, Bees

Maintenance

Survives periodic droughts and even occasional mowing. Leafs out and flowers if rains follow a dry period. Great for butterfly gardens. Purple tinge comes to upper leaves in full sun. Prefers to grow in low density. Treat for aphids if plant looks sick with soapy water, not pesticides. Propagation: seed, cutting, root division.

Comments

Blooms March-October. Mostly upright. Leaves oval with wavy edges. Fragrant flowers are green with purple tinges, appearing in the axis of leaves. The fruit is a pod, growing in pairs, with many small seeds attached to fluffy filaments. Larval host: Monarch Butterfly.
Previous Scientific Name(s): Synonym(s): Asclepias brevicornu

References

1) Griffith, Bryce, Omernick & Rodgers (2007). Ecoregions of Texas. 2) https://www.wildflower.org/plants/result.php?id_plant=ASOE. 3) https://portal.torcherbaria.org/portal/taxa/index.php?taxon=Asclepias+oenotheroides&formsubmit=Search+Terms. 4) http://bonap.net/TDC/Image/Map?taxonType=Species&taxonId=1429&locationType=County&mapType=Normal. 5) https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=30290#null, 6) https://www.wildflower.org/expert/show.php?id=10705#:~:text=They%20say%20that%20milkweeds%20can,so%20timing%20is%20very%20important.
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About the Region

New Braunfels, the location of our Fall 2024 Symposium, straddles both the Edwards Plateau Ecoregion and the Blackland Prairie ecoregion. Interstate 35 divides the city of New Braunfels; its path through the city closely parallels the boundary of these two ecoregions, with the Edwards Plateau on the west side and the Blackland Prairies region to the east. 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 four host chapters (New Braunfels, Lindheimer, Guadalupe, and the Hill Country chapters) are located in one or both of the ecoregions above. However, the eastern portion of Guadalupe County also falls within the Post Oak Savanna ecoregion. Annual rainfall averages 35 to 45 inches, with higher averages to the east. A wide variety of hardwood trees are found, including several species of oaks, elms, and in the Bastrop area, loblolly pine (Pinus taeda). Grasses and forbs dominate in the open savannas, with most common grass being little bluestem. Ranching, agriculture, and fire suppression have allowed woody species to encroach on the once-open savannas.

Source: Wildflowers of Texas by Michael Eason