Griffiths, Annual Report of the Missouri Botanical Garden 20: 87, 1909
Holotype (as O. gilvescens); Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Herbarium; Unless indicated otherwise, all specimens originally submitted as O. phaeacantha
What is Opuntia gilvescens?
Opuntia gilvescens is a widespread, medium-sized cactus. It occurs from Oklahoma all the way to central Arizona and southern Nevada. It is often confused with O. phaeacantha, in part because there is no slot for it in most guidebooks.
The authors have found it in OK (Arbuckle Mountains and west), in western TX, in many parts of NM as well as in AZ, southern portions of NV, UT, and CO, and in the mountains of the eastern CA Mojave Desert. Similar-appearing prickly pears have been found in the mountains east of Palm Springs, CA.
O. gilvescens has round or obovate cladodes that are generally dull. Main branches rest upon the ground and other branches rise to 70-80 cm. O. gilvescens is often a symmetrical plant. Mature plants may be 1 m across Cladodes may be 20 × 25 cm, but they are often smaller. Spines are not numberous, often there are only 2 major spines, but there may be 1-4 on first-year growth. The tips of spines are translucent.
Stigmas are green, pale green, or yellow-green. Anthers are yellow or cream-colored. Filaments are yellow but can darken towards the base. Many O. gilvescens flowers have a blush of red at the bases of the interior tepals, but some individuals may have rust-colored veining that can darken or spread as the flower ages. Cacti with all-yellow flowers may be found. Also, some cacti have pink flowers as in parts of southern UT. Fruit is round-bottomed or barrel shaped, but may occasionally have a narrow base, ripening to pink, reddish, or even greenish-pink. Flesh is greenish or pink-green, sometimes dark. Seeds are about .75 cm across with a 1 mm rim.
Plants from southwest NM and adjacent AZ are often pale; sometimes they have rhombic or more elongate joints and pale spines. Plants from the Mojave Desert area often have round pads with fewer than average areoles and a few pale spines. Plants from the Chihuahuan Desert of Mexico and into central Texas are often dark in appearance; they may become strongly red-purple in winter and the spines can be black.
In central New Mexico, O. gilvescens fits the type description well. Some southern populations, such as populations on the east side of the Sandia Mountains and down into Socorro County, and again in the Alamogordo area, often have wide, curved pads creating an interesting potato chip look.
See the original description. O. gilvescens is hexaploid.