Scientific: Dermatophyllum secundiflorum (formerly Calia secundiflora and before that Sophora secundiflora)
Common: Texas mountain laurel or mescalbean (referring mainly to the red seeds)
Family: Fabaceae (Leguminosae)
Origin: Chihuahuan Desert in mountain systems of western Texas and southern New Mexico into old Mexico.

Pronounciation: Der-ma-to-PHIL-um se-cun-da-FLOR-um

Hardiness zones
8-16, 18-24
USDA 9-11

Landscape Use: Accent, large informal hedge, background screen, spectacular small patio tree, mixed low water use garden landscape.

Form & Character: Upright and rounded, clean, robust and healthy (unless suffering from catepillar damage).

Growth Habit: Woody, evergreen perennial large shrub or small tree, slow growth rate to 10 to 25 feet in height with slightly less spread, multiple trunks.

Foliage/texture: Pinnately compound dark green foliage, pinnately compound with 3 to 5 pairs of leaflets to 2 inches long, silky hairy beneath, infrequently gray and tomentose, attractive chocolate brown trunk; medium coarse texture.

Flowers & fruits: Flowers are intoxicatingly fragrant, blue-violet, rarely white in color, developing on 2 to 6 inch terminal racemes that are initiated during the summer of the previous growing season, flowers fade to light purple or white as they age; attract carpenter bees. Flower buds are initiated in August and remain latent until the following late February/early March; fruits in clusters are a brownish gray, constricted pod with loose extremely hard red seeds that mature in early fall, reddish orange seeds are poisonous containing the alkaloid cytisine; fruits are relatively indehiscent with very hard pod coats.

Seasonal color: In Phoenix, Texas mountain laurel flowers appear in late February and early March.

Temperature: Summer heat-loving, summer maritime climates (the Pacific fog) decrease vigor.

Light: Full sun, NO shade.

Soil: Well-drained soil is a requirement for sustainalble performance.

Watering: In Phoenix, established plants will need to be deeply irrigated about once every 1 to 2 weeks during summer to maintain a lustrous canopy of foliage.

Pruning: The extent and type of pruning depends on landscape use. Little to no pruning is necessary if it is used as a background plant. If used as a multiple trunk tree, then only very occassionaly (once every couple of years) raise the crown base. Beware that Texas mountain laurel is VERY SLOW to recover if severely pruned. In any case, PLEASE don't shear this wonderful plant. If it is to be an informal hedge, make sure to prune by heading back lightly individual stems and branches ONLY during late April to early May.

Hey plant freaks, check out this very cool gray-leaf variant! Some are trying to market this wonder plant as a cultivar called 'Silver Peso', others as 'Silver Sierra'.

Propagation: Seed, double acid scarify, is difficult, but is the only commercially viable. Air layering has been tried with limited success.

Disease and pests: Texas root rot in formerly agricultural soils with a pathological history if drainage is poor. Green leaf variant can be fed upon by caterpillars of a small, white Pyralid moth during late summer and fall. The caterpillars are attracted to succulent vegetative growth so one management key is to not over fertilize your Texas mountain laurel shrubs in an attempt to speed their growth. Severe infestations of the catepillars may be treated with treatments of Bacillus thuringiensis, a bacterial biological control agent that only kills the pest. On smaller plants, inspect and remove the catepillars by hand or with the water spray from a garden hose. The gray leaf variant of Texas mountain laurel appears to be mostly immune to caterpillar attack.

Additional comments: Texas mountain laurel is quite slow growing and difficult to field dig and transplant. For landscape use, it is best to transplant larger 5 or 15 gallon nursery container stock into the landscape. In the end though this is a truly wonderful and beautiful, large shrub to small tree for many mesic or desert urban landscapes. For Phoenix landscapes, I prefer use of the silver variant due to its lesser tendency to suffer caterpillar damage during late summer.

Ethnobotany notes: American natives used the mescalbeans of Texas mountain laurel in many ways ranging from trade to jewelry and spiritual ceremonies.