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Scientific: Dermatophyllum secundiflorum (Synonyms: Calia secundiflora, 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: Floral accent, large informal hedge, background screen, spectacular small patio tree, mixed low water use garden landscapes.

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

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

Foliage/Texture: Dark green foliage, pinnately compound with 3 to 5 pairs of leaflets to 2-inches long, silky hairy beneath, infrequently leaves are silver gray and densely tomentose, attractive chocolate brown trunk; medium coarse texture.

A special phenotype: Hey plant freaks, check out this very cool silver gray leaf phenotype! Some nurseries are trying to market this wonder plant as a cultivar called 'Silver Peso', others as 'Silver Sierra'. Whatever the name, this phenotype is 'boss'.

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, flowers attract bees and butterflies. Flower buds are initiated in August of the previous year 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: Texas mountain laurel is summer heat-loving. In contrast, summer maritime climates (the Pacific fog) markedly decrease its vigor.

Light: Full sun, NO shade.

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

Watering: In Phoenix, established Texas mountain laurel 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. PLEASE do not shear this wonderful plant like was barbarically done to this brutalized specimen by the 'Horticultural clods of Phoenix' (aka 'Hort clods') that are (hopefully were) maintaining this commercial account. If it has to be an informal hedge, then make sure to prune it back lightly by selectively removing individual stems and branches ONLY during late April to early May.

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. The green leaf phenotype can/will 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 stimulate your Texas mountain laurel shrubs with extra water and fertilizer in an attempt to speed their growth, although the summer monsoon will often cause a late summer season flush of succulent 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 phenotype 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' leaf phenotype 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.