• Corpus ID: 89815628

Ajo Peak to Tinajas Altas: A flora in southwestern Arizona. Part 7. Eudicots: Cactaceae – Cactus Family

@inproceedings{Felger2014AjoPT,
  title={Ajo Peak to Tinajas Altas: A flora in southwestern Arizona. Part 7. Eudicots: Cactaceae – Cactus Family},
  author={Richard Stephen Felger and Sue Rutman and Marc A Baker and Jim Malusa},
  year={2014}
}

• R. Felger, S. Rutman, +1 author J. Malusa
• Published 2014
• Environmental Science

A floristic account is provided for the cactus family as part of the vascular plant flora of the contiguous protected areas of Organ Pipe Cactus National M onument, Cabeza Prieta National Wildlife Refuge, and the Tinajas Altas Region in the heart of the Sonoran Desert in southwestern Arizona. The modern native cactus flora includes 35 taxa i n 12 genera, plus 2 non-native pricklypears that are not established in the flora area. The over all cactus flora including fossils and nonnatives totals 39 taxa in 13 genera: at least 17 taxa are re presented by fossils recovered from packrat middens, two of which are no longer present in the flora are . This account includes selected synonyms, English, Spanish, and O’odham common names in when available, identification keys, brief descriptions, images, local and general distributional, n tural history, and ethnobotanical information. This flora is specimen-based with select d specimens cited. A new combination is proposed: Echinocereus coccineus Engelmann subsp. santaritensis (W. Blum & Rutow) M.A. Baker. Echinomastus erectocentrus var. acunensis is treated as synonym of Sclerocactus johnsonii . Club chollas in the flora area previously called Grusonia kunzei and G. parishii are correctly shown to be G. wrightiana and G. kunzei , respectively. Cactus diversity in the flora area ge nerally decreases from regions of higher and more predictable rainfall (east side of the flora area) to lower and less predictable rainfall (west side of the flora area). Sixt een taxa generally do not range westward from the flora area and five do not range eastward. Cylindropuntia, with 12 present-day taxa, is the most diverse cactus genus in the flora area as well as the Sono ran Desert. Also included is a discussion of convergent evolution of water-conserving adaptations in Peniocereus striatus and an African Euphorbia. This is the seventh contribution for this flora serie s published in Phytoneuron and available on the website of the University of Arizona Herbar ium. Felger, Rutman, Malusa , & Baker: Southwestern Arizona, Cactus Family 2 CACTACEAE – Cactus Family Cacti, especially organ pipe ( Stenocereus thurberi ), inspired the formation of the Organ Pipe Cactus National Monument. Some cactus species in the pre s nt–day flora are defining aspects of the landscape while others can only be seen if you diligently search for them. These cacti have provided people with significant food and beverages, the saguaro and organ pipe fruits being especially delicious and sought after. The local cacti also have been used for house construction, medicine, and for other practical as well as religious or ritual purpos es (e.g., Castetter & Bell 1937; Felger 2007). The yellow-spine prickly-pear, Opuntia engelmannii var. flavispina, occurs at former village and farming sites and may represent introductions and/or sel ections by Native Americans. Cactaceae is fourth largest family in the flora area (Felger et al. 2013a & b). The local cactus diversity includes 12 genera and 39 total taxa with 31 native modern species plus 1 hybrid and sever al varieties (Table 1). At least 18 taxa are represented by fossils recovered from packrat middens. Coryphantha vivipara and Cylindropuntia multigeniculata, collected by Ice Age packrats in Organ Pipe mountains, are not known from the flora area earlie r than 9600 years ago. Cylindropuntia, with 12 present-day taxa, is the most diverse cactus genus in the flora area as well as the Sonoran Desert. Organ Pipe has 32 modern, present–day native cactus taxa, C abeza Prieta has 25 taxa, and 14 occur in the Tinajas Altas region. Two prickly-pears, Opuntia engelmannii var. linguiformis, which is scarce, and O. santarita, which was cultivated, are the only non-native cactus report d in the flora and are not established or reproducing. Within the study area, the diversity of cactus taxa decrea ses s aridity increases from east to west. Sixteen taxa do not range westward from the flora a re nd five do not range eastward (Table 1). For example, the red–flowered mountain hedgehog cactus ( Echinocereus coccineus subsp. santaritensis), typically found in the high mountains of southeastern Ari zona, occurs in the flora area only at elevations over 1000 meters in the Ajo Mountains of O rgan Pipe, and does not range farther westward. In contrast, the many-headed barrel cactus ( Echinocactus polycephalus ) and beavertail cactus ( Opuntia basilaris var. basilaris) do not range farther eastward in flora area than the hyp rarid western part of the region. Peniocereus striatus and Lophocereus schottii are at their northern geographic limits along the southern margin of the flora area and the nearby Tohono O ’odham lands—their northern limits due to severity of winter freezing (see Felger et al. 2 013a). Five cacti are scarce and/or of limited distribution in the flora area and therefore of local cons ervation concern: Lophocereus schottii, Mammillaria thornberi, Opuntia engelmannii var. flavispina, Peniocereus striatus, and Sclerocactus johnsonii . Severe drought, probably correlated with climate change , has impacted a number of local cactus populations, especially Cylindropuntia leptocaulis , C. ramosissima , Mammillaria spp., and Sclerocactus johnsonii . The 37 present-day cacti in the flora area (Figure 1) re pres nt 22% of the total Sonoran Desert cactus flora, which includes about 180 taxa (approxim ately 128 species plus 27 subspecies and varieties, and 30 hybrids) in 21 genera (Felger et al., unpublis hed manuscript). Wiggins (1964), in his flora of the Sonoran Desert, included 160 taxa of cactus, of which about 15 percent were infraspecific taxa. The geographic extent used by Wiggins, based loosely n Shreve’s (1951) defining map, was considerably broader than newer concepts of the Sonoran Desert (e.g., Felger et al. 2001; Turner & Brown 1982). Furthermore, Wiggins included a number of cactus taxa clearly not even within the boundaries of Shreve’s concept of this desert. The cactus family includes about 1800 species in 125 genera, native to the New World with a single exception (A nderson 2001). Theft of cactus from the flora area is known to occur but the impact on local populations has not been quantified. Poaching is probably greatest along the U.S./Mexico border near Sonoyta and Felger, Rutman, Malusa , & Baker: Southwestern Arizona, Cactus Family 3 less common along the more remote public road systems. Some p aching undoubtedly occurs for commercial gain, but some plants are taken for personal co llecti ns or medicinal use. Although no formal records of poaching exist, a few instances are remembered. In 2002 a hole and a crumbled cigarette pack were all that remained of a tagged and ge o-ref renced night-blooming cereus (Peniocereus greggii ) plant that was part of a monitoring study at Organ Pipe ( S. Rutman, pers. observation). In another instance in the early 2000s, a Nat ional Parks ranger encountered a man dragging the bottom end of a chain-fruit cholla ( Cylindropuntia fulgida var. fulgida) from Organ Pipe into Mexico, to use as a treatment for a stomach ailm ent. When asked why he couldn't get the plant in Mexico, the man replied, “Because there are no more le ft ov r there.” At Bates Well in 2010, two smugglers with an unknown motive were discovered carrying a barr el c ctus ( Ferocactus) pierced by a long iron rod. Table 1. Local distributions of cactus taxa for the fl ora in southwestern Arizona. † = modern taxon also represented by a fossil specimen. †† = fossil taxon not found in the modern flora area. ** = non-native and not established (not reproducing) in the flora area. OP = Or gan Pipe Cactus National Monument, CP = Cabeza Prieta National Wildlife Refuge, TA = Tinajas Altas Regi on. Geographic limits: W = taxa generally not ranging westward from the flora area, and E = taxa generally no t ranging eastward from the flora area. Region Geographic limit Taxon