Calibanus hookeri – various sizes available

• Names and Synonyms:  
  Beaucarnea hookeri, Calibanus caespitosus, Dasylirion caespitosum, Dasylirion hookeri
• Common Names:  
  Mexican Boulder Plant
• Family:  
  Agavaceae; Nolinaceae
• Origin:  
  Grows in rocky grit on the tops of mountains in San Luis Potosi, Mexico
• Mature Size:  
  Caudex with leaves
• Height:  
  1-2'
• Width:  
  1-2'
• Cold Tolerance:  
  15 to 20°F, -9.4 to -6.7°C
• Heat Tolerance:  
  Extreme
• Light Requirement:  
  Full sun
• Water needs:  
  Very drought tolerant
• Maintenance:  
  Remove dried leaves as desired. Young plants grow with most of the caudex buried and should be allowed to remain this way for many years if your interest is in having a large plant. If lifted early, the caudex will grow very slowly, but will early on develop the bark fissures that make this species so appealing.
• Uses:  
  Excellent in containers to show off its caudiciform base. C. hookeri also makes an interesting specimen plant in the landscape. In mass plantings it is reminiscent of a coarse blue fescue grass. Useful in cactus, succulent and xeriscape gardens or caudiciform collections. Deer and rodent resistant.
• Propagation:  
  Can be propagated by seed. There are separate male and female plants.
• Special notes:  
  This evergreen succulent from north central Mexico has clumps of long thin leaves that emerge from a large swollen caudex which reaches 1 to 2 feet in diameter when mature. The stiff blue-gray green leaves are held upright in the center of the plant and arch down as they mature. These grassy leaves are tough but not stiff or pointed. They rise from a large rock shaped caudex, often raised above the ground, where the plant stores water. The dioecious flowers are small and hidden in the foliage and borne on foot long spikes in spring. Female plants eventually get brownish-red berries. The genus is named for Shakespeare's monster in The Tempest - Caliban. Although this plant was long considered the only species in a monotypic genus, a second species, Calibanus glassianus, with longer and broader blue leaves and a much larger inflorescence bearing bigger flowers was discovered in 1995 in Guanajuato.
• Research Links:
  
  http://www.smgrowers.com/products/plants/plantdisplay.asp?plant_id=289#
• http://davesgarden.com/guides/pf/go/62155/
• http://www.desert-tropicals.com/Plants/Agavaceae/Calibanus_hookeri.html
• http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=50822

Additional information