View source for Thelocactus

{{Treatment/ID
|accepted_name=Thelocactus
|accepted_authority=(K. Schumann) Britton & Rose
|publications={{Treatment/Publication
|title=Bull. Torrey Bot. Club
|place=49: 251. 1922
|year=1922
}}
|basionyms={{Treatment/ID/Basionym
|name=Echinocactus subg. Thelocactus
|authority=K. Sch umann
|rank=subgenus
|publication_title=Gesamtbeschr. Kakt.,
|publication_place=429. 1898
}}
|synonyms=
|hierarchy=Cactaceae;Cactaceae subfam. Cactoideae;Thelocactus
|hierarchy_nav=<div class="higher-taxa"><div class="higher-taxon"><small>family</small>[[Cactaceae]]</div><div class="higher-taxon"><small>subfamily</small>[[Cactaceae subfam. Cactoideae]]</div><div class="higher-taxon"><small>genus</small>[[Thelocactus]]</div></div>
|etymology=Greek thele, nipple, and Cactus, an old genus name, in reference to the tubercle shape
|volume=Volume 4
|mention_page=page 99, 207
|treatment_page=page 216
}}<!--

--><span class="statement" id="st-undefined" data-properties=""><b>Plants </b>erect, unbranched or branched and forming mounds, deep-seated in substrate or not. <b>Roots</b> diffuse or short taproots. <b>Stems</b> unsegmented, greenish [to pale blue-gray], spheric or flat-topped to short cylindric, 3–38 × 4–20 cm, glabrous; ribs usually 7–13[–25], absent in young plants [and some Mexican taxa], crests very deeply notched above each areole, thus ribs strongly tuberculate, 15–25 mm diam.; tubercles prominent, broadly rounded, conic, pyramidal, bilaterally compressed [or long decurrent]; areoles 6–20[–52] mm apart along ribs, groove connecting areole to spine cluster absent on youngest adults and conspicuous on older plants; areolar glands often conspicuous [or absent]; cortex and pith firm, not mucilaginous. <b>Spines</b> [1–](8–)12–30 per areole, white, yellow, or red [black], largest spines 0.2–1.5 mm wide; radial spines [0–](8–)12–20(–25) per areole, contrasting with other spines, straight [to curved, rarely almost hooked], 9–35(–45) mm, adaxial radial spines flat and bladelike or ribbonlike; central spines 0–4(–5) per areole, usually straight, sometimes somewhat curved, terete, flattened, or angled. <b>Flowers</b> diurnal, from adaxial or axillary extremity of areole, near stem apex, shallowly to deeply funnelform, [2.5–]4–8(–10) × [2–]4–6.5(–10) cm; outer tepals minutely fringed; inner tepals widely spreading, magenta or pink [white, yellow, or patterned with contrasting veins or transverse white band proximally and/or broad white margins and/or orange-red to crimson proximal portions], 28–50 × 5–12 mm, margins entire or fringed to denticulate; ovary scaly, hairless, spineless; scales 5–21, broad, margins scarious, minutely fringed; stigma lobes 7–13, reddish to orange or yellowish [or whitish], 4.5 mm. <b>Fruits</b> dehiscent through large basal pore, green to brownish purple [to magenta], spheric to short cylindric, (5–)7–18 × 6–12(–17) mm, not juicy, drying immediately after ripening, scaly, spineless, hairless; floral remnant persistent. <b>Seeds</b> black or very dark brown, short cylindric to pyriform, sometimes constricted above base, 1.4–2.5 × 1–1.75 mm; testa cells convex [or flat, sometimes with shiny, raised, reticulate sculpture of slightly protruding, narrow, straight anticlinal walls]. <b>x</b> = 11.</span><!--

-->{{Treatment/Body
|distribution=Arid regions;sw United States;Mexico.
|discussion=<p>Species 11 (1 in the flora).</p><!--
--><p><i>Thelocactus</i> is an assortment of morphologically primitive species groups, united primarily by fruit morphology (scaly, dehiscent through gaping poricidal attachment scars), which is shared with <i>Echinomastus intertextus</i>. Seed shape, however, is cylindric or pyriform, unlike the spheric or hemispheric seeds of <i>Echinomastus</i>. Chloroplast DNA evidence (C. A. Butterworth et al. 2002) places certain examined species of <i>Thelocactus</i> close to <i>Ferocactus</i> along with <i>Glandulicactus</i> and the Mexican genus Leuchtenbergia. Unfortunately, because <i>Thelocactus</i> is probably paraphyletic or polyphyletic (species originating from different ancestors), relationships of each species must be examined. Although <i>Echinomastus</i> was not included in that study, DNA evidence obtained by J. M. Porter et al. (2000) confirmed that genus is more closely related to <i>Sclerocactus</i> than to <i>Thelocactus</i>.</p>
|tables=
|references={{Treatment/Reference
|id=anderson1987a
|text=Anderson, E. F. 1987. A revision of the genus Thelocactus B. & R. (Cactaceae). Bradleya 5: 49–76.
}}{{Treatment/Reference
|id=glass1977a
|text=Glass, C. and R. A. Foster. 1977. The genus Thelocactus in the Chihuahuan Desert. Cact. Succ. J. (Los Angeles) 49: 213–220, 244–251.
}}
}}<!--

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-->{{#Taxon:
name=Thelocactus
|author=Allan D. Zimmerman;Bruce D. Parfitt
|authority=(K. Schumann) Britton & Rose
|rank=genus
|parent rank=subfamily
|synonyms=
|basionyms=Echinocactus subg. Thelocactus
|family=Cactaceae
|distribution=Arid regions;sw United States;Mexico.
|reference=anderson1987a;glass1977a
|publication title=Bull. Torrey Bot. Club
|publication year=1922
|special status=
|source xml=https://bibilujan@bitbucket.org/aafc-mbb/fna-data-curation.git/src/bb6b7e3a7de7d3b7888a1ad48c7fd8f5c722d8d6/coarse_grained_fna_xml/V4/V4_405.xml
|subfamily=Cactaceae subfam. Cactoideae
|genus=Thelocactus
}}<!--

-->[[Category:Treatment]][[Category:Cactaceae subfam. Cactoideae]]