Sideroxylon occidentale, bebelama

Large shrub or tree with leaves and growth form that look similar to Lycium or Condalia, but can grow much larger. Bebelama has spine-tipped branches and acquires furrowed bark at a fairly young age. Usually not common, but widespread in Sonora in thorn-scrub and the eastern part of the Sonoran Desert, where it generally grows near washes or sheltering rocky outcrops.

This species has not been found in Arizona, but has been seen within 20 kilometers and could potentially be found in lower parts of the Tumacacori Highlands west onto the Tohono O'odham Nation.

The Forgotten Flora of la Frontera

About 1,500 collections from within 100 kilometers of the Arizona border in Sonora yielded noteworthy records for 164 plants including 44 new species (12 non-native) for Sonora and 12 (six non-native) for Mexico, conservation species, and regional endemics. Many common widespread species were poorly collected. Southern range extensions (120 species) were more numerous than northern extensions (20), although nine potentially occur in Arizona. Non-native species dispersed along highways and escaped from cultivation.

Koeberlinia spinosa, allthorn

Uncommon shrub in Sonora and Arizona, but can grow in thickets where it does occur. As the name implies it is "all thorns" with unnoticeable leaves and small flowers. It grows primarily in the Sonoran Desert, semi-desert grasslands and into the Chihuhuan Desert. Often it will creep along the ground in a low, impenetrable thicket, but can sometimes ascend and become large and tree-like.

Phaulothamnus spinescens

An often overlooked or unrecognized shrub that looks similar to Lycium and some Condalia species. The fruiting plant has clusters of smallish (~5mm) berries with whitish/clear flesh and with a single dark seed in the middle. They look somewhat like little eyes and have common name of snake-eyes in English and mal de ojo in Spanish. In Sonora it grows primarily in thorn-scrub/TDF understory, in the lusher parts of the Sonoran Desert, and sometimes in semi-desert grassland.

Bursera laxiflora

In our region Bursera laxiflora is a thorn-scrub species and commonly grows in more exposed parts of this plant community. In Sonora it often has a less ascending and more shrub-like stature than B. fagaroides and B. lancifolia. In my experience its northernmost extension is an exposed hill on the road between Magdalena and Cucurpe.