The flowers are large pink-magenta with a red throat and a white zone
Thelocactus bicolor ssp. schwarzii (Backeb.) N.P.
Taylor CCI 5: 14 (1998).
Lectotype: Cact. Succ. J. Gr. Brit.
12: 84 (1950).
Conservation status: Listed in
CITES appendix 2
Tamaulipas, ssp. schwarzii has a limited distribution in
the Tamaulipan Thorn Forest, where only two localities are known.
Habitat: Occurring in Tamaulipan Thorn Shrub on rocky outcrops.
Published in: Cact. Succ. J. Gr. Brit. 12:
Ferocactus bicolor var. schwarzii N.P.
Published in: Cact. Succ. J. Gr. Brit. 41:
Thelocactus bicolor var. schwarzii
Published in: Bradleya 5: 61 (1987).
This is taxon is characterised by tight, reddish radial spines and no
central spines, though, rarely, plants with a single central spine can
be found amid those normally lacking this feature.
This is a small-sized species usually solitary.
Stem: Bluish green, ovoidal, up to 9cm tall, 7 cm in diameter or
more; But in cultivation plant can slowly grow up to 25 cm tall.
Ribs: Distinct with rounded tubercles, this entity has a higher
number of ribs about 13.
Central spines: Absent (may however appear sporadically);
Radial spines: 13 to 16 ochre to reddish, with yellowish tips.
20-30 mm long, straight, acicular.
Flowers: Very showy 65-85 mm wide, magenta with a red throat and
a white zone above it.
Cultivation: It is a summer
grower species easy to cultivate. Water regularly from Spring to Autumn,
but do not overwater, can become too elongated if compost is too rich.
Requires full sun or light shade and careful watering to keep plant
compact with strong coloured spines. Needs good drainage and very porous
potting mix, In Winter, keep dry.
Reproduction: From seed, since the plant rarely produces plantlets.
conspecific taxa, varieties, forms and of
plants belonging to the Thelocactus
Taxon has lots of
synonyms ( like many other
cacti) whit several controversial
varieties and subspecies and comprises a multitude of different
forms, but where each form is linked to others by populations of plants
with intermediate characteristics):
bicolor var. bicolor (Frost hardiness -7°C )
T. bicolor var. bolaensis (Frost hardiness -12°C ) Origin:
Coahuilafrom Sierra Bola, up to 20 cm tall.
T. bicolor var. commodus It has been described as
having only one, porrect, central spine, but with a careful
observation it is possible to notice that the upper central spines are
so appressed to the stem that they can be easily mistaken for radials.
- T. bicolor var. ellipticus is
referable to bicolor.
T. bicolor var. flavidispinus (Frost hardiness -12°C
) Texas 8cm in diameter, 5cm tall.
T. bicolor var. heterochromus
T. bicolor var. pottsii (Referable to bicolor var.
- T. bicolor var. rhodophthalmus is referable to
T. bicolor var. schottii (Frost hardiness -12°C) coming
from the Big Bend area Texas, Chihuahua) characterized by a very long,
papery upper spine.
- T. bicolor var.
schwarzii 1 0° F (-12°C) Tamaulipas
- T. bicolor var. texensis is an invalid name
for a Texas form.
- T. bicolor var. tricolor (Frost hardiness -7°C ) A
form with bright red spines. Plants with these characters can be found
around Saltillo, Coahuila.
- T. bicolor var. zwakii, It is not sufficiently
distinct to deserve a subspecies rank.
Thelocactus bicolor cv. INERMIS