Opuntia santa-rita (Santa Rita purple prickly pear)

Opuntia santa-rita (Griffiths & Hare) Rose

Opuntia chlorotica Engelm. & J.M. Bigelow var. santa-rita Griffiths & Hare

Opuntia violacea Engelm. var. santa-rita (Griffiths & Hare) L.D. Benson

Opuntia chlorotica Engelm. & Bigelow var. santa-rita Griffiths & Hare

Santa Rita purple prickly pear, Santa Rita pricklypear

Kingdom	Plantae	Plants, but not fungi, lichens, or algae
Subkingdom	Tracheobionta	Vascular plants—plants with a “circulatory system” for delivering water and nutrients
Division	Magnoliophyta	Flowering plants, also known as angiosperms
Class	Magnoliopsida	Dicotyledons—plants with two initial seed leaves
Subclass	Caryophyllidae	Cacti, many other succulents, carnivorous plants, and leadworts
Order	Caryophyllales	Includes cacti, carnations, amaranths, ice plants, and many carnivorous plants
Family	Cactaceae	Succulent (water-storing) plants, often spiny
Genus	Opuntia	Prickly pears
Species	santa-rita

About plant names...

Santa Rita Prickly Pear is native to Texas, Arizona, and northern Mexico.

Identification: This cactus usually has distinctive purple coloring. Pads are 4-8" (10-20 cm), tinged with purple; turning entirely purple when very dry. Spineless, or pink or reddish spines less than 1½" (3.8 cm) long. There are also tiny reddish-brown, loosely attached spines called glochids, which are irritating and difficult to remove. Flowers are lemon yellow, becoming more orange as they age. Flowers occur on tops of pads. Fruit is barrel-shaped, smooth, about 1" (2.5 cm) x 1½" (3.8 cm).

Cochineal insects (Dactylopius confusus) attack prickly pear cacti, leaving a whitish, wool-like substance behind. Although these insects are regarded as annoyances today, they were a source of brilliant red dye to the Aztecs.

Online References:

Opuntia santa-rita at Southeastern Arizona Wildflowers and the Plants of the Sonoran Desert

Opuntia santa-rita at George and Audrey DeLange's Arizona wildflower site

Opuntia santa-rita at the Arizona Sonora Desert Museum Sonoran Desert Digital Library

Opuntia santa-rita on Desert-tropicals.com

Opuntia santa-rita at the Lady Bird Johnson Wildflower Center

Opuntia santa-rita on

Opuntia santa-rita on eFloras

References:

Bowers, Nora and Rick; Tekiela, Stan, Cactus of Arizona Field Guide, Adventure Publications Inc., 2008, p. 147.

Opuntia santa-rita description by Thomas H. Kent, last updated 25 May 2020.