Escobaria duncanii
(Syn: Escobaria dasyacantha var. duncanii)

Escobaria duncanii SB467 Cuatrocienegas, Coahuila, Mexico
It is a small, globular, winter hardy plant with many spines on tubercles.
 

Description: In the wild the C. duncanii is an inconspicuous and difficult cactus to identify, and usually rare.  It normally stays solitary, or branches slowly as it ages.  It will form condensed upright cylinders, densely covered with white spines with darker tips.
Stems: Mostly 1-2 cm across by 1-2 cm tall, hemispherical,  becoming short cylindric in age, but appearing conical due to spination.
Tubercles: Grooved on the upper side.
Spines: 30-75 per areole, slender and bristle-like, spreading, to 10 (22) mm long, pure white to brown, bristly with pink, red-brown to nearly black tips
Flowers: About 1 cm wide, not opening widely, nearly apical, pale whitie, brown, or pink with midribs darkest, stigmata green; perianth deciduous in flower.
Fruit: Mature fruits are elongate, about 1-2 cm long, bright red or pinkish-red, floral remnant caducous.
Seeds: Black, about 1.5 mm long, nearly globose with rim around basal hilum, pitted.
Blooming season: Flowers in April.

Similar Species: The green stigmas, deciduous perianth in fruit, and black seeds readily distinguish E. duncanii and E. missouriensis from all other species. E. duncanii differs from E. missouriensis by the former's southern distribution, more slender non-pubescent spines, and smaller seeds.  E. duncanii resembles a stunted, crevice-limited growth form of C. dasyacantha, but has caducous floral remnants.  It is closely related to C. zilziana Boedeker of Mexico.

 

Cultivation: Easy to cultivate in a very gritty substrate with much drainage. Water regularly in summer, but do not overwater (very rot prone).  It prefers a completely dry place during the winter.  Escobaria ducanni is also quite successful to grows outdoors in the rock garden, even though it does not grow very fast.  It spends the winter often covered by snow!  The only problem is their tender root system.  If they are over-watered they will rot, so they are best grown in a mineral mixture without any humus.  Probably they cannot be grown without protection in the coldest climates of northern Europe and Canada, but in an unheated greenhouse they will do fine. They can survive low temperatures (appr. -12 C).   Full sun to light shade
 

Scientific name:  Escobaria duncanii (Hester) Backeberg,
Cactac. Handb. Kakteenk., 5 : 2966, 1961

Origin:  New Mexico, central Sierra County; Texas, Brewster and Presidio counties; adjacent Mexico, Coahuila and Chihuahua.

Habitat: Cracks in limestone and limy shale in broken terrain in Chihuahuan desert scrub; at1,550 m in New Mexico.

Conservation status: Listed in CITES appendix 2.

Common Names include: Duncan pincushion cactus, Duncan's Snowball Cactus Duncan's, foxtail cactus, beehive-cactus

• Escobaria dasyacantha (Engelmann) Britton et Rose var. duncanii (Hester) N.P.Taylor, 1983
• Escobesseya duncanii Hester,
  Desert Pl. Life, 13 : 192, 1941, sine descr. lat.; et in Desert Pl. Life, 17 : 24, 1945; cf. Gray Herb. Card Cat.
• Escobaria duncanii (Hester) F.Buxbaum,
   Kakteen, Lief. 14, CVIIIc. (Jul. 1960), in obs.
  Coryphantha duncanii (Hester) L.D.Benson,
  Cact. Succ. Journ. (US), 41 : 189, 1969
• Escobaria dasyacantha (Engelmann) Britton et Rose var. duncanii (Hester) N.P.Taylor,
  Kakt. und And. Sukk., 34(7) : 157, 1983
• Mammillaria duncanii (Hester) D.D. Weniger, nom. nud.
• Escobaria dasyacantha subsp. duncanii

.

• E. dasyacantha ssp. dasyacantha
• E. dasyacantha ssp. chaffeyi
• E. duncanii (E. dasyacantha var. duncanii)
• E. tuberculosa (E. dasyacantha var. varicolor)