Opuntiads of the USA

Opuntia humifusa (Rafinesque) Rafinesque

O. humifusa has been lumped with a variety of southeastern Opuntia species, including O. austrina and O. ammophila. At this writing (2008) the Flora of North America still recognizes var. ammophila which is considered a distinct species herein. O. humifusa is considered synonymous with Opuntia compressa (Salisb.) J.F. Macbr., and you will often find references to O. compressa in the literature and on the World Wide Web.

Because O. humifusa appears to be closely related to O. macrorhiza, and because both species range into the center of the continent, they have been confused and perhaps hybrids exist in gardens here and there (further complicating efforts to differentiate the two). Over the past two centuries, O. humifusa may have been referred to as Opuntia italica, Opuntia rafinesquii var. minor, Opuntia vulgaris var. rafinesquii, Opuntia rubiflora, Opuntia rafinesquii, Opuntia vulgaris, Opuntia mesacantha, Opuntia cespitosa, Opuntia calcicola, Opuntia allairei, Cactus humifusus, Opuntia nemoralis, Opuntia fusco-atra and likely other names as well, such as O. pollardii (see Desert Tropicals Web site).

Opuntia humifusa is not a desert plant. Rather, it is an opportunist in areas that receive heavy rainfall or runoff part of the year but which can be quite hot and dry other parts of the year. Hence, it is often found in sandy soils, or on rock outcrops. It has been reported from New England, to the Midwest, to Mississippi, to Florida, and may even range into east Texas.

Flowers are typically yellow, but some with rose tints in the interior have been reported. Generally, O. macrorhiza is a larger species and has tuberous roots but this distinction is not universal, and it is possible O. humifusa may have enlarged roots.

In the past decade or two the species has been studied by various researchers including Lucas Majure, Barry Snow, James Doyle, Rita Songer, and Danny Green. Perhaps these studies will provide more information that can be reported here to create a better understanding of this species, what is is and what it is not.

The first 10 images were provided by Rita Songer who retains copyright (2007, 2008). Most images are of plants from Bradley Mountain (a.k.a. Arabia Mountain) near Lithonia, Georia (east of Atlanta, GA). The images shown here were taken in winter (February).

Opuntia humifusa in moss

Opuntia humifusa with scale-of-size marker

Opuntia humifusa

Opuntia humifusa with fruit from last leason

Opuntia humifusa fruit with ruler

Habitat shot showing bleak area where Opuntia humifusa is found on Bradley Mountain

Opuntia humifusa with fruit

Opuntia humifusa with colored size-scale

Close-up of image of cladode at immediate left

Garden plant, apparent hybrid between Opuntia humifusa and O. pusilla

Opuntia humifusa cladode with lichen, in sand scrub forest, Florida panhandle (photo by Mike Burnett).

The following images feature a plant from Canada (Point Pelee, Ontario) that was grow in a European garden (See Martin's opuntiads at Northern Nursery). The images were provided by Martin Tversted who retains copyright.

Opuntia humifusa, from Point Pelee, Ontario, Canada

The following set of images was provided by Craig Howe (2007, 2008) who retains the copyright. The various names (varietal names) may not reflect current treatements of O. humifusa; however, they do reflect L. Benson's division of the species and inclusion of Opuntia austrina (and other plants) into the species.

Opuntia humifusa var. ammophila (name no longer used, see O. ammophila)

Opuntia humifusa var. austrina (name no longer used, see O. austrina)

Opuntia humifusa flower, with unusual pink tink

Opuntia humifusa

The following images are from various Florida locations and were provided by Danny Green (Editor for the Southeast) who retains the copyright (2007, 2008).