Coryphantha macromeris |
Coryphantha dasyacantha |
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biznaga-partida partida, nipple beehive cactus |
Big Bend cactus |
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Habit | Plants profusely branched, ultimately forming low mats or hemispheric mounds to 100 cm diam., immature branches sometimes predominant, conspicuously tuberculate with projecting spines. | Plants usually unbranched (rarely 2–5 branches), white or brown bristly stem. |
Roots | ± succulent in largest, often massive and difficult to excavate. |
diffuse (rarely short taproots). |
Stems | deep-seated, aerial portion conspicuous, hemispheric to short cylindric, shape sometimes obscured by profusion of immature branches, 5–23 × (1.5–)4–8(–13.5) cm; tubercles unusually large, conspicuous, (10–)15–38(–45) × 6–15 mm, ± flaccid or flabby; areolar glands seasonally conspicuous; areolar grooves short, extending 1/2–3/4 distance from spines toward tubercle axils; parenchyma mucilaginous; pith narrow, ca. 1/10 of lesser stem diam.; medullary vascular system absent. |
spheric, becoming short cylindric in age, 4.5–10(–17) × (2–)3–4.5(–6) cm (1–3 × 2–5 cm in Davis Mountains, Texas); tubercles (4–)7–8(–12) × 3–5(–7) mm, moderately soft; areolar glands absent; parenchyma not mucilaginous, medullary vascular system absent. |
Spines | 7–21[–55] per areole; radial spines (3–)9–15(–18) per areole, white, gray, tan, or brown, (9–)16–25(–50) mm; subcentral spines 2–3 in adaxial part of areole; central spines (1–)3–8 per areole, (tan to) pale gray to black, abaxial central spine porrect or descending, others weakly appressed or ± projecting spines, slightly curved, usually angular in cross section (terete), sometimes flat and grooved on 1 side and rounded on the other, often slightly flexible, (15–)25–35(–55) mm, all equal or abaxial spine longest. |
26–42 per areole, white with red-brown to nearly black tips (brown to reddish brown with black tips in Davis Mountains); radial spines 21–31 per areole (12–22 in Davis Mountains), 6–9(–10) mm; subcentral spines several, appressed; central spines (3–)4–9(–11) per areole (2 in Davis Mountains), spreading, straight, longest spines 12–17 × 0.2–0.3(–0.4) mm. |
Flowers | apical or nearly so, 30–50(–60) × (30–)40–70 mm; outer tepals heavily fringed; inner tepals 20–25 per flower, bright rose-pink or magenta, often with darker midstripes and paler margins, 30–40 × 4.5–6 mm; outer filaments greenish white throughout or distally purplish pink; anthers bright yellow; stigma lobes 6–13, white or pale yellow, 3–6 mm. |
nearly apical, 15–30 × (10–)13–15(–22) mm, sterile distal part of flower tube 0–2 mm, shorter than stamen-bearing part; outer tepals conspicuously fringed; inner tepals 14 per flower, midstripes pinkish to brown or brownish green, proximally white, (7–)8–10(–12) × 1.5–3 mm; outer filaments white or colorless; anthers bright yellow; stigma lobes 4(–6), dark green to bright yellow, 1–2.5 mm. |
Fruits | dark green, ovoid to obpyriform or ellipsoid, (10–)13–25(–30) × 12–18 mm; floral remnant strongly persistent. |
bright red, clavate, cylindric, or narrowly ellipsoid, (7–)13–27(–35) × 3.5–6(–7) mm, not very succulent; floral remnant strongly persistent. |
Seeds | reddish brown, ± comma-shaped to spheric, 1.2–1.5 mm, finely and weakly raised-reticulate. |
black, subspheric, 1–1.2 mm, pitted. |
2n | = 22. |
= 22. |
Coryphantha macromeris |
Coryphantha dasyacantha |
|
Phenology | Flowering Feb–Sep; fruiting (May-)Aug–Dec. | Flowering Mar–Jul; fruiting (May-)Jun–Aug, ca (1 1/2)-(2 1/2) months after flowering. |
Habitat | Chihuahuan desert scrub, Tamaulipan thorn scrub, nearly all substrates including nearly pure gypsum, gravelly soils, usually sandy alluvium or clay, rarely crevices or steep slopes | Desert scrub with Larrea or Prosopis, on limestone, igneous rocks, gravelly bajadas, silty flats |
Elevation | 30-1700(-2000) m (100-5600(-6600) ft) | 800-1900 m (2600-6200 ft) |
Distribution |
NM; TX; Mexico (Chihuahua, Coahuila, Durango, Zacatecas)
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TX |
Discussion | Southern Texas populations of Coryphantha macromeris contain atypical individuals with proliferating small stems and shorter (stunted?) spines. Sexually mature stems branch from the tubercle axils, and the whole shoot becomes covered by immature branchlets. The immature branchlets proliferate profusely and asymmetrically faster than they can reach sexual maturity, obscuring the underlying symmetry of mature stems and forming irregular, asymmetric mounds. Such plants are the basis for C. macromeris var. runyonii (Britton & Rose) L. D. Benson, but they do not grow in pure populations. Therefore the name runyonii can not be used at varietal rank without including plants morphologically similar to typical C. macromeris from the Chihuahuan Desert. Stunted or immature Coryphantha macromeris are variable, keying to Coryphantha with some difficulty, often having only 5–7 radial spines and lacking central spines. The strongly mucilaginous cortex is a useful field mark; even small slices of living tubercle tissue are visibly and tangibly slimy. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Many published photographs and specimen citations purported to represent Coryphantha dasyacantha reflect misidentifications. Ripe fruits, with their strongly persistent floral remnant, provide the only simple way to distinguish C. dasyacantha from C. duncanii. The black fresh seeds of C. dasyacantha and related species usually provide immediate distinction from C. tuberculosa, C. sneedii, and C. vivipara, which have differently shaped, bright reddish brown fresh seeds. In addition, the greenish stigma lobes of C. dasyacantha, C. duncanii, C. chaffeyi, C. pottsiana, and certain Mexican taxa contrast with the violet or white stigma lobes of C. vivipara, C. sneedii, C. alversonii, and C. hesteri. Vegetatively, C. dasyacantha always is distinguishable from C. vivipara and C. sneedii by its lack of the unusually large druses described under 20. C. sneedii. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 4, p. 224. | FNA vol. 4, p. 230. |
Parent taxa | Cactaceae > subfam. Cactoideae > Coryphantha | Cactaceae > subfam. Cactoideae > Coryphantha |
Sibling taxa | ||
Synonyms | Mammillaria macromeris, C. macromeris var. runyonii, C. macromeris, C. pirtlei, C. runyonii, Lepidocoryphantha macromeris | Mammillaria dasyacantha, Escobaria dasyacantha, Escobesseya dasyacantha |
Name authority | (Engelmann) Lemaire: Cactées, 35. (1868) | (Engelmann) Orcutt: Cactography 1926(1): 5. (1926) |
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