Common Name: alluaudia
Type: Deciduous shrub
Family: Didiereaceae
Native Range: Southern Madagascar
Zone: 9 to 10
Height: 16.00 to 20.00 feet
Spread: 16.00 to 20.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: White
Sun: Full sun to part shade
Water: Dry to medium
Maintenance: Medium
Other: Thorns
Tolerate: Drought, Dry Soil
Culture
Best grown in evenly moist to dry, sandy loams in full sun to partial shade. Water when the soil drys during the growing season but greatly reduce watering during winter dormancy. Tolerant of drought once established. Propagate using stem cuttings. Hardy in Zones 9b(25°F)-11.
Noteworthy Characteristics
Alluaudia humbertii is a deciduous, succulent, small tree or large shrub native to semi-arid scrubland and thorn forests of southern Madagascar. It is often found growing in acid, sandy loams or red sands. Mature plants can reach 16-20' tall and equally as wide with a stout trunk and freely branched habit. The slender branches have thin, grey bark, range in form from procumbent to arched to upright, and are covered in spines reaching 0.75" long. Small, rounded, succulent leaves reaching 0.75" in diameter emerge from the branches during the rainy season and are dropped by the plant during the dry season. The small, pale green flowers bloom seasonally in axilary clusters located toward the terminal ends of the branches. These plants are dioeceous meaning that male and female flowers occur on separate individuals.
Genus name honors French explorer Charles A. Alluand (b. 1861).
The specific epithet humbertii honors Jean-Henri Humbert (1887-1967), a French botanist who collected extensively in Madagascar.
Problems
No major pest or disease problems of note. Water-logged or poorly drained soil will lead to root or stem rot.
Uses
A specimen or accent plant for xeriscaping, desert gardens, or rock gardens. Can be grown in a pot as a houseplant.