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Native Plant Society of Texas

Two Leaved Senna

Senna roemeriana

Other common name(s):

Twoleaf Senna

Family:

Fabaceae (Pea 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.

Central Great Plains, Chihuahuan Deserts, Cross Timbers, Edwards Plateau, High Plains, Texas Blackland Prairies
Limestone Plains
Chihuahuan Basins and Playas, Chihuahuan Desert Grasslands, Chihuahuan Montane Woodlands, Low Mountains and Bajadas, Stockton Plateau
Carbonate Cross Timbers, Eastern Cross Timbers, Grand Prairie, Limestone Cut Plain, Western Cross Timbers
Balcones Canyonlands, Edwards Plateau Woodland, Llano Uplift, Semiarid Edwards Plateau
Arid Llano Estacado, Shinnery Sands
Northern Blackland Prairie

Plant Characteristics

Growth Form

Shrub

Height

1
to
3
ft.

Spread

1
to
2
ft.

Leaf Retention

Deciduous

Lifespan

Perennial

Habitat and Care Requirements

Soil Type(s)

Clay, Limestone, Caliche, Well Drained, Dry

Light Requirement

Sun, Part Shade

Water Requirement

Low, Medium

Native Habitat

Grassland, Woodland

Bloom and Attraction

Bloom Color

Yellow

Bloom Season

Spring, Summer, Fall

Seasonal Interest

Seeds, Nectar, Larval Host

Wildlife Benefit

Butterflies, Birds, Bees

Maintenance

Very little maintenance needed. An attractive mounding plant. Forms large colonies. Difficult to transplant due to large tap root. Drought tolerant – too much water will cause rot. Native habitat: common in fields and open woods of Central and West Texas. WARNING: plants of this genus can cause poisoning and fatal illness in humans. Propagation: seed.

Comments

Blooms May-October. Mounded shape. Thick, gray leaves have a velvety texture and are uniquely divided into two leaflets. Showy, bright yellow pea-like flowers occur in the axis of upper leaves. The fruit is a leathery pod containing several seeds. Larval host: Cloudless Giant Sulphur.
Previous Scientific Name(s): Cassia roemeriana

References

1) Griffith, Bryce, Omernick & Rodgers (2007). Ecoregions of Texas. 2) Miller, George O., Landscaping with Native Plants of Texas 2nd Ed., 2013, pg 53. 3) https://www.wildflower.org/plants/result.php?id_plant=SERO8. 4) http://bonap.net/TDC/Image/Map?taxonType=Species&taxonId=11697&locationType=County&mapType=Normal, 5) https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=505174#null, 6) Wasowki, Andy and Sally, 1991, Native Teas Plant, Landscaping Region by Region, 182. 7) https://www.soilcropandmore.info/crops/Weeds/UvaldeWeedSite/sero.htm, 8) https://www.nativesoftexas.com/two_leaf_senna.htm, 9) chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://plants.usda.gov/DocumentLibrary/factsheet/pdf/fs_sehe3.pdf

Learn about how to propagate Texas native plants.

Material Treatment Method Collection References
Seed Scarification Successful propagation involves ensuring good seed-to-soil contact by lightly covering the seeds with soil, as twoleaf senna seeds have a hard coating that benefits from scarification to enhance germination rates. Germination rates can be low, so plant more seeds than necessary. Generally, it takes three to four years for the plant to bloom after propagation by seed. Collect pods in late summer when they have turned brown and begun to dry, but before they split open. Air dry before storing. 1) https://www.wildflower.org/plants/result.php?id_plant=SERO8 2) https://www.picturethisai.com/wiki/Senna_roemeriana.html 3) https://www.botanikks.com/plants/cassia-roemeriana-scheele/545069/1
Clump Division Replant the sections in new pots or areas in the garden. It usually takes about a year for the plant to recover and bloom after division. In early spring, before new growth, gently lift the plant from the soil, and use a sharp knife to divide the plant into sections. Ensure that each section has sufficient roots and rinse them with water. https://www.botanikks.com/plants/cassia-roemeriana-scheele/545069/1
Semi-harwood Cutting Remove the leaves from the lower half of the cutting and dip the cut end of the stem into a rooting hormone powder or gel. Insert the treated cutting into a pot filled with well-draining potting mix, such as a combination of perlite and peat moss. Make a hole in the mix using a stick or your finger, and then place the cutting into the hole, firming the soil around it gently. Place the potted cutting in a warm, bright location with indirect sunlight. Maintain humidity by covering the cutting with a plastic bag, then water the soil lightly, keeping it moist but not waterlogged. The optimal time to propagate through cuttings is during late spring to early summer, to take advantage of ideal temperature and light conditions and natural growth cycles. Cut a 4-6 inch long stem section from the plant with at least one node and some leaves. https://www.picturethisai.com/wiki/Senna_roemeriana.html

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