Cumarinia odorata

Cumarinia odorata is a species of small cactus that often forms irregular clumps with a few branches. The stems are globular or shortly cylindrical in shape, with a dark green epidermis. They grow to 4 cm in height and 3 cm in diameter, with a slightly sunken and glabrous apex. The stems are covered in soft, flaccid cylindrical tubercles. They are blunt, with a shallow groove on top, and measure up to 1 cm in length and 0.4 cm in width. The axils are bare.

At the ends of the tubercles are areoles, which are covered in white wool when young. These have 3-4 strongly hooked central spines, which are black or dark reddish to yellow in color and 2-2.5 cm long. There are also 7-9 radial spines, which are white or yellow with a brown tip and measure 0.8-1 cm in length.

The small, funnel-shaped flowers open during the day. They are narrow and yellow-pink in color. The flowers first appear at an early stage of the plant's life and are self-fertile. They measure 1.5-2 cm in length and 0.8-1.2 cm in diameter. The stamens are inserted in two rows, and have white filaments and golden-yellow coffee bean-shaped anthers.

The fruits are small, narrow, and cylindrical. They are light green in color with a slight pinkish tint, and measure 1.5-2 cm in length. Inside the fruit, the black seeds are egg-shaped and laterally compressed.

This species is native to northeastern Mexico, specifically to San Luis Potosí, southern Nuevo León, and southwesterm Tamaulipas, where it is mainly found in desert or dry scrubland biomes. It grows on limestone slopes and canyons at altitudes of 670 to 1430 meters above sea level.

This species is cultivated primarily as an ornamental. It may be propagated vegetatively via cuttings, or via seeds. It needs full sun exposure to fully develop and flower at an early age. It is sensitive to rot due to overwatering, and it therefore must be grown in a well-draining substrate. Furthermore, it can tolerate relatively low temperatures (down to -5 ºC / 23 ºF) so long as its substrate is kept dry.

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