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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)

Caliche, Clay, Dry, Limestone, Well Drained

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

Larval Host, Nectar, Seeds

Wildlife Benefit

Bees, Birds, Butterflies

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. WARNING: plants of this genus can cause poisoning and fatal illness in humans. Native habitat: common in fields and open woods.

Description

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

2026 Fall Symposium Logo

This low-elevations region of Texas extends inland from the barrier islands, about 60 or so miles, and stretches from Brownsville to Louisiana. In total, it covers about 9.5 million acres, with a high point of 150 feet in elevation. More than 1000 species of plants can be found in this region. On the southern end, species more common in Mexico (such as Sabal mexicana) and Central America occur.

The barrier islands provide us with dune systems, and clay flats to the inland side, which have species found in these areas alone. Many plants here, such as Ipomoea pes-caprae (beach morning glory), can be found throughout tropical regions of the globe. I’ve encountered the same species on the beaches of Guam.

Once inland, vast marshes and wet prairies occur. Occasionally, oak (Quercus fusiformis) groves can be found. Common grasses include species of Bothriochloa, Paspalum, and Sporobolus; eastern gamagrass (Tripsacum dactyloides); and switchgrass (Panicum species). Many rivers and creeks cut through the Gulf Prairies, and along these riparian areas various species of trees, Sabal minor, and other plants adapted to clay soils can be found. Due to overgrazing, farming, and fire suppression, woody species such as mesquite (Prosopis glandulosa) and huisache (Acacia farnesiana), and invasive species such as chinaberry (Melia azedarach), Brazilian pepper (Schinus terebinthifolius), and Chinese tallow (Sapium sebiferum) have increased and displaced our native flora.

Source: Wildflowers of Texas by Michael Eason