Opuntiads of the USA

(by Joe Shaw and Dave Ferguson)

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Opuntia Country No. 1
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Opuntia Country with
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Northern Patagonia Cactus Trip

Opuntia pottsii Salm-Dyck

O. pottsii is a small Opuntia, sometimes just a few inches tall. The plants can be confused with other smaller opuntias including O. polyacantha and O. macrorhiza if they are only casually observed, or if they are growing among grasses, etc. In flower however, O. pottsii is sometimes easily noticed because it may have pink, red, organge, or salmon flowers, whereas other smaller opuntias are (typically) yellow-flowered.

Additionally, O. pottsii often assumes a distinctive growth form when actively growing. Plants grow upright from from a single central stem; the pads do not crawl along the soil as is often the case with many small Opuntia species.

Benson (1983) proposed a very broad concept of O. macrorhiza that included O. pottsii as a distinct variety of that species. Others have described O. ballii (see separate page) as a distinct species or as a variety of O. pottsii, but O. ballii is not formally recognized herein. Nonetheless, O. pottsii is variable and three varieties are recognized by the authors (to be described as Website is filled out with images).

A disribution map is provided by the Flora of North America (online), but the map is conservative because the plant has been observed in more northerly and more easterly areas by the authors. Some of the images on this page depict plants from as far north as Santa Fe, NM and Kingman, AZ.

Technical Description

Succulent subshrub: evergreen, clumping plants growing from a central stem that arises from a taproot, the central root is tuberous or enlarged and can emit a white sap; plants may have few pads, often 8-10 or less; pads do not typically crawl along the soil surface, the pads are often held erect from the central stem.

Cladodes: pads are variable but often obovate, rhomboid, or nearly elliptical, and may be slightly stipitate, pads are firm but can shrivel in winter and lay upon the soil, 4-10 cm diameter by 8-15 cm long.

Glochids: adaxial in areole, tufted, yellow to rust-brown, 2-4 mm, sometimes darker and longer with age, present in most areoles.

Spines: often 3-4 per areole in distal half of pad, many be 0 or 5, often acicular but can be flat or twisted, white, gray-white, or with rust tones, gray in age, 2 cm to 5 cm, proximal spines may be deflexed if multiple spines.

Flowers: tepals typically orange, red, pink, or salmon, or yellow, filaments variable colors, anthers yellow, stigma cream, 4 cm to 7 cm diameter.

Fruits: typically elongate and with stipe, may be elongate-pyriform or obovoid, 2 cm by 3-5 cm; green, tan, with red tones when mature.

Seeds: orbicular, suborbicular or irregularly so, 4-5 mm diameter, obvious girdle 0.4 mm, may be thick or uneven.

Opuntia pottsii, June 2009, greater Kingman, AZ area	Opuntia pottsii, June 2009, greater Kingman, AZ area	Opuntia pottsii, June 2009, greater Kingman, AZ area
Opuntia pottsii from West Texas, sometimes called Opuntia ballii but not recognized as a distinct taxon herein	Opuntia pottsii, late winter, (var. montana), Albuquerque, NM	Close-up of plant at immediate left.
Opuntia pottsii (var. montana), from river bottom sandy soil, Albuquerque, NM (photo copyright 2008, Mike Burnett)	Opuntia pottsii (var. montana), Bandelier National Monument, New Mexico, late May 2006, elevation ca. 6,500 ft.	Opuntia pottsii in bud--same plant as in photo at left; several of the ovaries are swollen (boxed in red)--apparently from insect galls
Opuntia pottsii (var montana), Bandelier National Monument, late May, 2006	Close-up of plant to left, elevation ca. 6,500 ft., plant shows characteristic growth habit from central stem	Opuntia pottsii (form found in Albuquerque area)
Opuntia pottsii, Albuquerque, NM, late winter 2006	Opuntia pottsii, Albuquerque, NM (form found in Albuquerque area)	Opuntia pottsii, Albuquerque form
Opuntia pottsii, Albuquerque form	Opuntia pottsii, close-up of plant at left, March 2006	Opuntia phaecantha, growing with O. polyacantha and O. pottsii in immediate vicinity, Bandelier National Monument, New Mexico, late May 2006