| | The genera of Cactaceae |
The plants succulent; opuntioid; not ‘low and very compacted’. The stems spiny, or not spiny. The plants creeping or scrambling, or climbing (weakly), or terrestrial and self supporting; shrubby, moderately branched (without dimorphic branches); with cladodes to without cladodes. The cladodes when present, without midribs. The plants prostrate to erect; shrubby; solitary, or clustering; to 0.5–5 m high. The branches differing in form from the main stem, or resembling the main stem. The main stem not remaining dominant; trunk, when present more or less cylindrical. The branches flattened (obovate or elliptical,), or cylindrical; when flattened, not combining a straight upper margin with a curved lower one. The stems segmented, or not segmented; not ribbed and grooved (sometimes with faint ribs linking the areoles). The ribs when present, tessellate. The plants not conspicuously tuberculate. The areoles associated with tubercles to not tubercle-associated (i.e., sometimes on slight protuberances); distant; spirally disposed, or spirally disposed and borne along the margins of the flattened branches, or scattered on the surfaces; small, simple. The flowering areoles resembling the non-flowering ones. The areoles hairy (with long hairs); with glochids (these caducous, sometimes minute); with spines, or without spines. The spines when present, paired, or clustered (soon deciduous); 2–3(–6); 0.2–0.3 cm long; showing little or no difference between radials and centrals. The mature stems with much reduced leaves. Leaves of mature stems abortive, minute to small; caducous fleshy; terete.
Flowering at night and during the day. The flowers lateral (when arising close to the apex, not actually terminal); one per areole; sessile; medium-sized to large; 3–10 cm long; regular. The receptacle conspicuously produced beyond the ovary into a tubular hypanthium. The hypanthial tube elongated and gradually dilated beyond the ovary, thick, stemlike, persistent; not naked; with scales (these tiny). The axils of the scales of the hypanthial tube not naked (with areoles and glochids). The hypanthial tube spineless. The perianth members erect or reflexing; yellow to orange, or red. Stamens adnate to the perianth; separated from the perianth by a conspicuous ring of hairs; exserted beyond the perianth; coherent (reuniting above to form a tube through which the pistil protrudes, the erect anthers surrounded by perianth hairs). Pollen grains 12 aperturate (with very small spines and perforations).
The mature fruit 2.2–5.5 cm long; ellipsoidal (with a deep umbilicus); green, or white, or brown (-ish), or red (-ish); naked (?), or not naked; spiny, or with glochids, or spiny and with glochids, or without spines; without persistent floral remains; fleshy; indehiscent (?). The seeds 3–4 mm long; white (-ish); i.e., the funicular envelope, very conspicuously hairy; globose or sub-globose (sub-globose), or pyriform; slightly laterally compressed; encased in their bony arils. Cotyledons fleshy, foliaceous.
Natural Distribution. Eastern and northeastern Brazil.
Classification. 5 species. Subfamily Opuntioideae. Tribe Opuntieae.
Cf. Hunt (1967).
Images. • Tacinga palmadora: www.cactuspro.com.
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’.
