Beiselia mexicana

Origin
Beiselia mexicana is endemic to Mexico, specifically native to the state of Michoacán. It was first discovered and described by the German botanist Karlheinz Beisel in the 1980s. It is the sole species in the genus Beiselia.

Habitat
In its natural environment, this species thrives on steep, rocky limestone slopes within tropical deciduous forests. It grows in arid to semi-arid conditions at altitudes ranging from 500 to 650 meters above sea level. The plants are well-adapted to surviving intense heat and long dry seasons by storing moisture in their succulent, pachycaul trunks.

Description
Beiselia mexicana is a unique, deciduous pachycaul tree, highly prized for its prehistoric appearance and distinctive spines.

Caudex & Trunk: It develops a thick, succulent, and conical trunk that can reach up to 10-15 meters in height in the wild. The bark is grayish-green and is armed with prominent, conical prickles (spines), giving it a rugged look similar to certain cacti or Pachypodiums.

Foliage: The leaves are pinnate, consisting of 7 to 13 serrated leaflets. They are bright green and emerge from the tips of the branches during the rainy season.

Flowers: It produces small, inconspicuous yellowish-green flowers. The fruit is a three-angled capsule containing a single seed.

Cultivation: This is a slow-growing and highly sought-after species for pachycaul enthusiasts. It requires full sun to maintain its stout form and a very well-draining mineral substrate. Watering should be regular during the summer growth phase but stopped almost completely during the winter dormancy period.