Jatropha dioica

Jatropha dioica forms colonies from subterranean rhizomes.[4] The arching, succulent stems reach a height of 20–60 cm and have few branches. They are tough[5] and sufficiently flexible to be tied into overhand knots without breaking.[3] The orange rootstock spreads to a length of around 1 m.[6] Leaves are arranged simply, alternately, or fascicularly and are clustered on short shoots extending from the stems.[5] They are subsessile and have entire margins. The leaves of the nominate variety are linear and measure up to 6 × 1 cm, whereas the leaves of J. dioica var. graminea may be 2 to 3-lobed and measure up to 6.5 × 0.5 cm. Male inflorescences are clustered cymes. Their flowers possess 3.5 mm sepals, 5 mm petals, and 10 stamens. Female flowers are urceolate with 5 mm petals that are recurved at the tips.[7] Blooming takes place during the spring and early summer.[8] The fruit is a 5 × 12 mm[7] capsule[5] divided into 1 to 2 cells. Seeds are subglobose and measure 1 × 1 cm.[7]

Latex is produced by a non-articulated laticifer network composed of 5 to 7 cells.[9] It changes from clear-yellow to blood red as it is exposed to air,[6] hence its Spanish name sangre de drago, "dragon's blood". The roots contain riolozatrione (C₂₀H₂₆O₃), a diterpene with antimicrobial properties.[10] Sheep and goats experience severe gastroenteritis, vomiting, and abdominal pain upon consumption of the plant.[11] Leatherstem is able to safely absorb a relatively high amount of zinc (6249 mg/kg).[12]

The nominate variety occurs in southern and western Texas,[13] Tamaulipas, Nuevo León, and from Durango to Oaxaca. J. dioica var. graminea is found from Chihuahua to Zacatecas[14] as well in the Trans-Pecos of Texas.[5] Its type specimen was collected in Jimulco, Coahuila.[14]

Jatropha dioica is traditionally used in the treatment of dental issues such as gingivitis, loose teeth, bleeding gums, and toothache.[15] The latex is an astringent[6] and may also be used as a red dye.[8] Leatherstem is sometimes cultivated as an ornamental in xeriscapes or rock gardens.[16]

Sangre de drago acts as a nurse plant for small cacti such as Lophophora species.[17] The seeds are eaten by white-winged doves (Zenaida asiatica).[6]

• Dehgan, Bijan; Grady Linder Webster (1979). University of California Publications in Botany. Volume 74: Morphology and Infrageneric Relationships of the Genus Jatropha (Euphorbiaceae). University of California Press. ISBN 978-0-520-09585-4.