''Thelocactus macdowellii'', called the Chihuahuan snowball, is a species of

cactus A cactus (: cacti, cactuses, or less commonly, cactus) is a member of the plant family Cactaceae (), a family of the order Caryophyllales comprising about 127 genera with some 1,750 known species. The word ''cactus'' derives, through Latin, ...

native to northeastern Mexico. It has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. It includes the full range of cultivated p ...

Description

''Thelocactus macdowellii'' is a small, spherical cactus, typically 4 to 10 centimeters tall and 4 to 12 centimeters wide, with a yellowish apex covered in woolly hairs. It has 30 or more ribs, each with 5 to 7 millimeter high, conical, rhombic warts at the base. The areoles, initially woolly, bear 15 to 25 needle-shaped marginal spines, 1.5 to 2 centimeters long, and 3 to 4 central spines, each 3 to 5 centimeters long and straw yellow. The flowers are funnel-shaped, 4 to 8 centimeters wide and up to 4 centimeters long, varying in color from rose red to magenta. The ovaries are smooth and have broad scales.

Distribution

Endemic to the Mexican states of Coahuila,

Nuevo León Nuevo León, officially the Free and Sovereign State of Nuevo León, is a Administrative divisions of Mexico, state in northeastern Mexico. The state borders the Mexican states of Tamaulipas, Coahuila, Zacatecas, and San Luis Potosí, San Luis ...

, and the Chihuahuan Desert, ''Thelocactus macdowellii'' grows on scrubland and limestone hills in a very restricted area at an altitude of 1500 meters.

Taxonomy

First described as ''Echinocactus macdowellii'' in 1894 by Leopold Quehl, with the specific epithet honoring the Mexican gardener and plant collector José Alberto McDowell. The species was later placed in the genus ''Thelocactus'' by William Taylor Marshall in 1947

References

External links

* * {{Taxonbar, from1=Q2416664, from2=Q15009367 macdowellii Endemic flora of Mexico Flora of Northeastern Mexico Plants described in 1947