Isotype; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium
Original Description
What is Opuntia chlorotica var. gosseliniana?
O. chlorotica var. gosseliniana is one of three recognized varieties in the O. chlorotica complex, together with var. chlorotica and var. santa-rita. The varieties intergrade where they meet, yet var. gosseliniana is notable for consistently purplish to bluish pads and a tendency to form multiple ascending branches. The variety has often been confused with purple-pad taxa such as O. macrocentra, but flowers, fruits, and growth form align it with O. chlorotica as clarified by Ferguson (1988) and subsequent work on relationships.
Details
Shrubs: Usually small, commonly under 1 m tall, branching into several ascending stems; older trunks and branches may develop slender, needle-like spines. Cladodes: Circular to broadly obovate, glaucous bluish-green strongly flushed pink- to purple-violet, especially in stress or cool seasons. Areoles: Moderately spaced, with tan to brown glochids and variable spine production. Glochids: Present in areoles, fine and barbed, tan to reddish-brown. Spines: Highly variable—absent to several per areole, commonly restricted to upper areoles; slender, straight to flexuous, from short and stiff to long and pliant, sometimes to ~10 cm; colors cream to bright yellow, orange, reddish-brown, or nearly black. Buds: Blunt-tipped, not narrow-acute. Flowers: Yellow, typically with pale stigma lobes; commonly about 5–7.5 cm across. Fruits: Elliptic to short-cylindric, smaller and more slender on average than in var. chlorotica and var. santa-rita. Seeds: Typical for the complex, pale and lenticular.
Cytology
Diploid.
Similar or Sympatric Species
Opuntia chlorotica var. chlorotica — greener pads, larger fruits.
Opuntia chlorotica var. santa-rita — bluish pads, often taller shrubs.
Opuntia macrocentra — darker pads, red flower centers.
Opuntia setispina — gray pads, usually white spines.
Opuntia phaeacantha — common nearby, green pads, stout spines.
Opuntia camanchica — low-spreading, widely spaced areoles.
Other Notes
Native primarily to Sonora, Mexico, with a limited incursion into extreme southern Arizona (Tohono O’odham Nation), where it is uncommon in the wild. The cultivated purple-pad selection often sold as O. santa-rita ‘Tubac’ likely corresponds closely to var. gosseliniana in overall aspect and fruit size.
For more information, see:
Shaw & Ferguson (2019), Tucson area Opuntia, the prickly pears; Ferguson (1988), Opuntia macrocentra Eng. and Opuntia chlorotica Eng. & Big.; Majure et al. (2012), Phylogeny of Opuntia s.s.
