Ancistrocactus scheeri

(Salm-Dyck) Britton & Rose

Cact. 4: 4. 1923.

Common names: Root cactus
Illustrated
Basionyms: Echinocactus scheeri Salm-Dyck Cact. Hort. Dyck. 1849, 155. 1849
Synonyms: Ancistrocactus megarhizus (Rose) Britton & Rose Sclerocactus scheeri (Salm-Dyck) N. P. Taylor
Treatment appears in FNA Volume 4. Treatment on page 210. Mentioned on page 208, 211.

Plants unbranched (unless injured) until very old age, then few branched from ground level, precociously conspicuous. Roots long, fleshy, tuberlike taproots with bulbous swellings, sometimes having bulbous secondary-roots, frequently horizontally oriented. Stem cylindric to club-shaped and stipitate, or spheric, to 17 × 8 cm. Spines: radial spines 13–28 per areole, translucent yellowish, tips redbrown, longest spines 6–28 × 0.15–0.55 mm; central spines 3–4 per areole; abaxial central spine 1 per areole, hooked (very rarely straight), ± terete or adaxially flattened, generally whitish or light-brown, sometimes adaxially dark striped with brown to black, 12–38 mm; adaxial central spines (2–) 3 per areole, erect, straight, dorsiventrally compressed, abaxially tan to whitish, adaxially brown to dark reddish-brown, 19–50 mm. Flowers: inner tepals consistently bright green to yellowish (rarely pink to pale reddish). Fruits 19–35 mm. 2n = 22.


Phenology: Flowering Nov–Mar.
Habitat: Tamaulipan thorn scrub, plains and low hills, sandy, loamy, silty, or gravelly soils [rarely on shale]
Elevation: 20-500 m

Distribution

V4 392-distribution-map.gif

Tex., Mexico (Nuevo León), Mexico (Tamaulipas)

Discussion

The roots of Ancistrocactus scheeri are diagnostic at all ages; frequently they are horizontally oriented, sausage-shaped or otherwise strongly tuberlike, but always separated from the stem by a fragile constriction, in contrast to the short, succulent, vertical taproots of A. brevihamatus. When separated from the tuberlike roots, stems of A. scheeri in horticulture will develop their peculiar succulent root systems, even in the artificial environment of a container.

Seedlings and immature plants of A. scheeri often have narrowly cylindric stems and numerous tightly appressed, pectinately arranged, short radial spines. With age, the stems broaden distally and new spines are longer, coarser, and less tightly appressed.

Adult plants of Ancistrocactus scheeri and A. brevihamatus are relatively similar above ground. The stems of immature A. brevihamatus, however, are not obscured by spines and are often flush with the soil surface, whereas those of A. scheeri are nearly hidden by spines and fully exposed above the soil.

Ribs on the stems of Ancistrocactus scheeri seem straighter and better defined than ribs of A. brevihamatus, even prior to sexual maturity.

Selected References

None.

Lower Taxa

None.

... more about "Ancistrocactus scheeri"
sometimes adaxially dark striped with brown +  and black +
1.2 cm12 mm <br />0.012 m <br /> (3.8 cm38 mm <br />0.038 m <br />) +
abaxially tan +  and whitish adaxially brown +
1.9 cm19 mm <br />0.019 m <br /> (5 cm50 mm <br />0.05 m <br />) +
cushionlike +
deciduous +  and persistent +
newer +  and maturity +
elongate +
1.2 cm12 mm <br />0.012 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
Allan D. Zimmerman +  and Bruce D. Parfitt +
(Salm-Dyck) Britton & Rose +
hardened +
Echinocactus scheeri +
triangular +
proliferating +
flattened +  and cylindric +
Root cactus +
mucilaginous +
tuberculate +
notched +
Tex. +, Mexico (Nuevo León) +  and Mexico (Tamaulipas) +
20-500 m +
not separating +
2.5 cm25 mm <br />0.025 m <br /> (4 cm40 mm <br />0.04 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
15 cm150 mm <br />0.15 m <br /> (30 cm300 mm <br />0.3 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (15 cm150 mm <br />0.15 m <br />) +
2.5 cm25 mm <br />0.025 m <br /> (3.1 cm31 mm <br />0.031 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
white;pink tinge;white;pink tinge;dull;tan;yellowish;brownish purple;suffused pink;green +
indehiscent +
persistent +, long +  and deciduous +
15mm;25mm +
ovoid +  and cylindric +
1.9 cm19 mm <br />0.019 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
succulent +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
Tamaulipan thorn scrub, plains and low hills, sandy, loamy, silty, or gravelly soils [rarely on shale] +
1.7 cm17 mm <br />0.017 m <br /> (2.4 cm24 mm <br />0.024 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
deciduous +  and persistent +
rudimentary +
flat +  and terete +
nearly +  and microscopic +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
tuberculate +
fluted;spheric;depressed-spheric or club-shaped +
1.8 cm18 mm <br />0.018 m <br /> (2.9 cm29 mm <br />0.029 m <br />) +
6mm +  and 28mm +
0.015 cm0.15 mm <br />1.5e-4 m <br /> (0.055 cm0.55 mm <br />5.5e-4 m <br />) +
deciduous +  and persistent +
Flowering Nov–Mar. +
mucilaginous +
older +  and young +
ridgelike +  and nipple--shaped +
distinct +
indistinct +
fringed +
arillate +  and strophiolate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
minutely +  and papillate +
spheric;helmet-shaped or reniform +
Illustrated +
translucent yellowish +
straight +
deciduous +  and persistent +
13 (?) +  and 28 (?) +
flattened +  and acicular +
decurrent +
8 cm80 mm <br />0.08 m <br /> (10 cm100 mm <br />0.1 m <br />) +
dark gray-green +  and pale blue-green +
0cm;17cm +
spheric +, cylindric +  and club-shaped +
succulent +
0cm;8cm +
rose-pink +, yellowish +, green +  and white +
tuberculate +
Ancistrocactus megarhizus +  and Sclerocactus scheeri +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Ancistrocactus scheeri +
Ancistrocactus +
species +
flat +  and weakly convex +
dull +  and glossy +
branched +  and unbranched +
epiphytic;epiphytic;epiphytic +
barrel-shaped +  and spheric +