Agave heteracantha var. splendens
Agave univittata var. carchariodonta
This succulent is native to Mexico (Hidalgo, Tamaulipas, Guanajuato, Queretaro) commonly cultivated as an ornamental on other regions. It grows at high elevations (900-1000 m) on mountain limestone slopes and valleys, in the desert of Sierra Madre Orientale.
Usually, this Agave grows in an individual and open rosette, up to 30 cm tall and 120 cm wide. Compared with other agaves, it forms relatively few leaves: these usually are not more than 20. Leaves can get up to 90 cm long; they are lanceolate and accuminated, rough and rigid. The margins have broad, flat, light coloured spines. Leaf colour is quite variable, from acid/olive-green to silver-green, and present a lighter centre stripe. Leaves present also a terminal stout spine, pale brown, 2,5-5 cm long. The inflorenscence can can get up to 3-6,and flowers, in groups of 3-8, are 50 mm long, with greenish-yellow tepals.
This slow-growing Agave does well in containers or in well-drained, porous soils outside. They do well from full sun to light shade, and its heat tolerance is excellent. Water it after the soil got dried. In winter, it needs watering once every 1-2 months. Even if it is theoretically hardy to -3° C – particularly when dry- it is best to avoid severe freezing temperatures.
Propagation can be done by basal suckers: remove them in spring or summer, let the cuttings dry, then put them in compost. You can also use seeds.
The species name “xylonacantha” means “with woody spines”, referring to the broad wood colored spines on the leaves margins.