Bunched Cory Cactus
(Coryphantha ramillosa subsp. ramillosa)


Other Scientific Names: Mammillaria ramillosa


Other Common Names: Big Bend cory cactus, whiskerbush, whiskerbrush pincushion cactus, Big Bend mammillaria


Status: Federal and State Threatened


Global Rank: G2G3T2T3


State Rank: S2S3


Global Location: Bunched cory cactus is only known from West Texas in southern Brewster and Terrell counties. It also occurs across the Rio Grande in Chihuahua and Coahuila in northern Mexico.


Description: Bunched cory cactus is a succulent perennial usually with solitary, unbranched stems 3-9 cm tall and usually 3-7 cm wide, without mucilage in the stem interior. The stems are covered in spine-tipped cone-shaped projections 6-20 mm long, each with a groove on the upper side that extends from the tip to the base. Spines arising from each of these projections are numerous, but are not so dense that they hide the stem completely. Some of the spines (radial spines) form a ring around the tip, somewhat similar to the spokes of a bicycle wheel, except the spokes are irregularly spaced and twisted or curving as well as straight. Other spines (central spines) arise interior to the radial spines and point somewhat outward and away from the stem. There are typically 13-16 radial spines, although rarely there can be as few as 9 or as many as 20 per cluster. These radial spines are typically white or gray and usually reach 1-2 cm long. Usually longer than the radial spines, the three to four (rarely six) straight or somewhat curved central spines vary from white to gray to dark brown. The upper central spines are between 1.7-3.9 cm long and the lower central spines are 2.2-4.3 cm long. Bunched cory cactus flowers are pink to red-purple and 3.5-6.5 cm long, and the outermost petals have smooth edges. The egg-shaped to round fruits are 1-2.5 cm long and green at maturity. The seeds are brown or yellowish to reddish.



Bunched cory cactus usually has one unbranched stem and smooth, not fringed, flower petals.



Bunched cory cactus has spine-tipped cone-shaped projections, each with a groove on the upper side that extends from the tip to the base. In the illustration, seventeen light-colored radial spines arise exterior to four longer central spines (three upper, light-colored central spines and one lower, darker-colored central spine). Bunched cory cactus can have 9-20 radial spines and 3-4 central spines.


Similar Species: Big-needle pincushion cactus (Coryphantha macromeris) usually forms colonies up to 1 m across composed of many multi-branched individuals. Stems of big-needle pincushion cactus also have spine-tipped projections with a groove on their upper side, but the groove arises from the tip and extends half way down the projection. Flower petals of big-needle pincushion cactus are fringed, not smooth. The =2.5 cm, green fruits of Texas cone cactus (Neolloydia conoidea) greenish-brown or tan and dry at maturity and contain black or gray seeds. See the table below for more detailed, but important characteristics to differentiate between bunched cory cactus, big-needle pincushion cactus, and Texas cone cactus. All measurements given are typical lengths, though measurements (rarely) can occur outside these. For unabridged measurements, see references below.

Species

Central spine length (cm)

Radial spine length (cm)

Flower length (cm)

Bunched cory cactus

1.7-3.9 (upper)
2.2-4.3 (lower)

usually 1-2

3.5-6.5

Big-needle pincushion cactus

3-7

usually 1.5-2.5

usually 3-5

Texas cone cactus

0.9-1.7 (upper)
usually1.7-2.8 (lower)

usually 0.6-1.2

2.5-3.2



Big-needle pincushion cactus can form large colonies of individuals.Image courtesy of Mike Powell.



Texas cone cactus generally has shorter spines than bunched cory cactus.


Habitat: Rocky limestone flats, hills and mesas of the Chihuahuan Desert.



Life Cycle Events: Flowering occurs August to November, and occasionally as early as April.


Survey Season: Although the plant is visible year-round, bunched cory cactus is most easily detected while in bloom August to November.


Comments:

  • A geographically distant, yellow-flowered variant of bunched cory cactus in Mexico has been described as Coryphantha ramillosa subsp. santarosa.
  • Based on recent findings, the purple-flowered bunched cory cactus (Coryphantha ramillosa subsp. ramillosa) are more common than initially thought.


For additional information see:

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