Ancistrocactus

(K. Schumann) Britton & Rose

Cact. 4: 3. 1923.

Etymology: Greek ankistron, fish hook, referring to hooked centr al spines, and Cactus, an old genus name
Basionym: Echinocactus subg. Ancistrocactus K. Schumann Gesamtbeschr. Kakt., 292, 334. 1898
Treatment appears in FNA Volume 4. Mentioned on page 97, 98, 197, 198, 20.

Plants erect, unbranched (few branched from near base), sometimes deep-seated in substrate with only broad top visible. Roots diffuse, short, succulent taproots, or tuberlike. Stems unsegmented, dark green or dark gray-green to pale blue-green, spheric to cylindric, sometimes stipitate, 2–9 (–15) × 2–8 (–10) cm; ribs 8 or 13 (0 in young, tuberculate plants), indistinct (in A. brevihamatus) or distinct (in A. scheeri), crests deeply notched adaxial to each areole, making ribs prominently tuberculate; tubercles slightly coalesced into ribs with advancing age of plant, ± conic, protruding 1 cm or less on young plants and of ribs on adults; areoles ca. 12–18 mm apart along ribs, nearly circular at sexual maturity, newer areoles more elongate, on oldest parts of stem adaxially forming narrow grooves extending to axils, felted; areolar glands often conspicuous within grooves, hemispheric; cortex and pith conspicuously mucilaginous. Spines 10–26 per areole, sparse to densely obscuring stems, grayish, whitish, or yellowish, reddish or blackish in proximal and distal portions, acicular or somewhat flattened, to almost papery, minutely canescent; longest spines 9–25 (–45) × 0.4–0.8 mm; radial spines 7–22 per areole, straight, longest spines 5–18 (–29) × 0.1–0.5 mm; central spines (3–) 4 (–5) per areole (solitary abaxial central spine plus straight, flat adaxial central spines), principal central spine porrect, hooked (absent on immature plants and youngest adults of some A. brevihamatus populations). Flowers diurnal, near stem apex at adaxial edges of areoles on young adults, at axillary ends of short areolar grooves in older plants, funnelform, often narrowly so, expansion often restricted by adjacent spines, 2.5–4 × 1.5–4 cm; outer tepals entire to denticulate; inner tepals seldom showy: white, brown, pink, yellow, or green (brightest green in some A. scheeri), 2.5–17 (–24) × 0.6–5 (–7) mm, margins entire; ovary sparsely scaly, spineless, hairless; scales minutely fringed; stigma lobes 4–10, white, green, yellowish, or rose-pink, 1.5–2.5 mm. Fruits indehiscent, green, sometimes suffused pink or brownish purple, drying to yellowish, tan with dull pink tinge, or white, ovoid to cylindric, (9–) 15–25 (–31) × (3–) 6–9 mm, weakly succulent (sometimes drying to a papery shell), scaly, spineless, hairless; floral remnant persistent. Seeds black or very dark reddish-brown, spheric to helmet-shaped or reniform, 1.5–2 mm, glossy, papillate or minutely so; testa cells flat to weakly convex. x = 11.

Distribution

Arid regions, sw United States, Mexico

Discussion

Species 2 (2 in the flora).

Ancistrocactus is sympatric with three other hook-spined species: Glandulicactus uncinatus, Ferocactus hamatacanthus, and Hamatocactus bicolor. Ancistrocactus has only straight radial spines (Glandulicactus has strongly hooked abaxial radial spines), broadly rounded tubercles of ribs (those of Hamatocactus bicolor and Ferocactus hamatacanthus var. sinuatus are laterally compressed), and plants of reproductive age are much smaller than plants of Ferocactus hamatacanthus var. hamatacanthus.

Selected References

None.

Key

1 Roots short, conic taproots or diffuse, without constriction between stem and root; radial spines 7-14 Ancistrocactus brevihamatus
1 Roots fleshy, tuberlike taproots with bulbous swellings and/or bulbous secondary roots, always separated from stem by fragile constriction; radial spines 13-28 Ancistrocactus scheeri
... more about "Ancistrocactus"
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 +
(K. Schumann) Britton & Rose +
hardened +
Echinocactus subg. Ancistrocactus +
triangular +
proliferating +
flattened +  and cylindric +
mucilaginous +
tuberculate +
notched +
Arid regions +, sw United States +  and Mexico +
not separating +
Greek ankistron, fish hook, referring to hooked centr al spines, and Cactus, an old genus name +
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 +
succulent +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
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 />) +
Green (?) +, Yellow (?) +, Pink (?) +, Brown (?) +  and White (?) +
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 />) +
5mm +  and 18mm +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
deciduous +  and persistent +
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 +
adjacent +  and radial +
blackish +, reddish +, yellowish +, whitish +  and grayish +
straight +
deciduous +  and persistent +
7 (?) +  and 22 (?) +
flattened +  and acicular +
decurrent +
stipitate +  and unsegmented +
8 cm80 mm <br />0.08 m <br /> (10 cm100 mm <br />0.1 m <br />) +
dark gray-green +  and pale blue-green +
2cm;9cm +
spheric +  and cylindric +
succulent +
2cm;8cm +
rose-pink +, yellowish +, green +  and white +
tuberculate +
adventitious +
tuberlike +
epipetric +  and epiphytic +
Ancistrocactus +
Cactaceae subfam. Cactoideae +
flat +  and weakly convex +
dull +  and glossy +
epiphytic;epiphytic;epiphytic +
barrel-shaped +  and spheric +