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| The genera of Cactaceae |
San Pedro cactus.
Including Acantholobivia Backeb., Acanthopetalus Y. Itô, Andenea Fric (nom. inval.), Aureilobivia Fric, nom. inval., Chamaecereus Britton & Rose, Chamaelobivia Y. Itô (nom. inval.), Cinnabarinea Fric ex F. Ritter, Echinolobivia Y. Itô (nom. inval.), Echinonyctanthus Lem., Furiolobivia Y. Itô (nom. inval.), Helianthocereus Backeb., Heterolobivia Y. Itô (nom. inval.), Hymenorebulobivia Fric (nom. inval.), Hymenorebutia Fric ex Buining, Leucostele Backeb., Lobirebutia Fric (nom. inval.), Lobivia Britton & Rose, Lobiviopsis Fric (nom. inval.), Megalobivia Y. Itô (nom. inval.), Mesechinopsis Y. Itô, Neolobivia Y. Itô, Pilopsis Y. Itô (nom. inval.), Pseudolobivia (Backeb.) Backeb., Rebulobivia Fric (nom. inval.), Salpingolobivia Y. Itô, Scoparebutia Fric & Kreuz. ex Buining, Setiechinopsis (Backeb.) de Haas, Soehrensia Backeb., Trichocereus (A. Berger) Riccob.
The plants succulent; condensed-cactoid (often, at least at first), or cerioid (then sometimes dwarf, e.g. in Chamaecereus); low and very compacted in their entirety (e.g., Pseudolobivia), or not ‘low and very compacted’. The stems spiny (sometimes fiercely so); globose, or shortly cylindric, or elongate cylindric; apically depressed (sometimes, when globular), or not apically depressed; neither cephaliate nor pseudocephaliate. The plants terrestrial and self supporting; branched, or unbranched; prostrate to erect; shrubby to tree-like (mainly), or neither shrubby nor tree-like; with well formed trunks (rarely, e.g. in E. terscheckii), or not developing conspicuous trunks; solitary, or clustering; to 0.02–6 m high. The stems columnar, or not columnar. The branches differing in form from the main stem, or resembling the main stem. The main stem more or less cylindrical. The branches cylindrical. The stems not segmented; at least usually ribbed and grooved. The ribs few to many; borne spirally, or longitudinal. The grooves wide to deep and narrow. The plants conspicuously tuberculate (between or beneath the areoles), or not conspicuously tuberculate. The tubercles spirally disposed, or borne in longitudinal series. The areoles associated with tubercles, or not tubercle-associated; closely approximating, or distant. The components of adjacent areoles so extensively covering the mature plant body as to obscure any ribs or furrows (e.g., E. haematantha), or not obscuring details of the plant body. The areoles spirally disposed, or borne in longitudinal series; simple; usually woolly; without glochids; with spines (few to many, occasionally absent from some areoles). The spines clustered; (1–)4–100; 0.1–15 cm long; with radials and centrals differentiated, or showing little or no difference between radials and centrals. Central spines when manifest, 0, or 1 (often), or 1–10; conspicuously forming a cross (rarely), or not forming a cross. Radial spines 2–30(–55). The spines usually including some hooked members, or never hooked. The mature stems leafless.
Flowering during the day (mostly), or at night and during the day. The flowers usually lateral (but sometimes subterminal, e.g. in Leucostele); one per areole; hairy, funnelform, or campanulate, or salver-shaped, the perianth limb broad; sessile; large; (2–)4–25 cm long; regular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium; not naked; with scales; spineless. The pericarpel usually with numerous narrow scales bearing dense hairs, sometimes bristles, but no spines. The hypanthial tube ornamented like the pericarpels; not S-shaped; not naked; with scales. The axils of the scales of the hypanthial tube not naked (densely hairy, sometimes bristly). The hypanthial tube spineless. The perianth white, or yellow, or orange, or red, or pink; limb relatively large. The perianth segments relatively short, broad (usually), or elongate, relatively narrow (e.g., E. coronata); blunt, or pointed, or apiculate. Stamens adnate to the perianth (variously inserted in the throat and tube); not exserted; usually in groups (with the uppermost members displaced and their filaments forming a membranous ring in the throat); coherent, or free of one another.
The mature fruit 1–6.5 cm long (poorly recorded); globose to ovoid; more or less naked, or not naked (then with scales and/or hairs); without spines; fleshy; globose to ovoid, with scales and/or hairs to more or less naked. The seeds black; globose or sub-globose to ovoid; not encased in bony arils; without a mucilage sheath. The testa dullish; verrucose, or spotted (minutely). Cotyledons reduced or vestigial.
General anatomy. Medullary bundles present (at least in some spp.), or absent.
Natural Distribution. Ecuador, Chile, S. Brazil, Bolivia, Paraguay, Uruguay, Argentina.
Classification. About 130 species. Subfamily Cactoideae. Tribe Trichocereeae.
Cf. Hunt, 1967.
Images. • Echinopsis aurea: © Zoya Akulova (2007). • Echinopsis aurea: © Zoya Akulova (2007). • Echinopsis silvestrii and E. leucantha: Britton & Rose (1922). • Echinopsis oxygona (as multiplex) and E. turbinata: Britton & Rose (1922). • Echinopsis aurea, Copiapoa coquimbana, Lophophora williamsii: Britton & Rose (1922). • Echinopsis cinnabarina (as Lobivia), with Echinocereus sciurius, Echinocereus fendleri, Echinocereus X-roetteri (as lloydii) and Rebutia minuscula: Britton & Rose (1922). • Echinopsis aurea, with Copiapoa coquimbana and Lophophora williamsii: Britton & Rose (1922). • Echinopsis chamaecereus (as Cereus silvestrii): Bot. Mag. 138 (1912). • Echinopsis chamaecereus H. Friedrich & Glaetzle.: L.W. photo. • Echinopsis eyriesii (Turpin) Pfeiff. & Otto (as Echinocactus), Bot. Reg. 1707, 1835.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2018 onwards. The genera of Cactaceae: descriptions, illustrations, identification, and information retrieval. Version: 14th November 2021. delta-intkey.com’.
