Velvet Mesquite (Prosopis velutina) grows at elevations below 4,000 to 5,000 feet in desert washes and grasslands. It is the dominant tree species along streams and river beds. There the velvet mesquite forms dense thickets and woodlands, or bosques, from the Spanish word for forests. There are three common species of mesquite; the honey mesquite (Prosopis glandulosa), screwbean mesquite (Prosopis pubescens), and velvet mesquite. The velvet mesquite is the largest of the mesquite species. It is a low-branched, broad spreading thorny shrub or small tree with a well-developed crown. It can grow as a single-trunked tree about 30 feet tall, and just as wide, with a two foot diameter trunk. The bark of velvet mesquite is reddish-brown and smooth when young. On older trees the bark becomes gray-brown, rough, thick, and shredded into long, narrow strips. Two inch-long yellow thorns grow in pairs at the base of each leaf on the young branches. Leaves grow alternately on the branch. The leaves themselves are bipinnate, compound, about 3-6 inches long, and pointed. The leaf has two sets of compound leaves, usually with four major leaflets and 10-20 narrow minor leaflets 1/3 to 1/2 inch long, which grow opposite each other on the stem. The leaves are dark to dusky green with a gray, hairy surface and paler undersides. The leaves fold closed at night. The flowers are yellow-green, drooping catkins about 2-3 inches long. The flowers are tiny, but there are hundreds in a catkin. It is a member of the pea family. These photos were taken on the Walnut Canyon/White Canyon trail on March 23, 2016.

Blue Palo Verde (Parkinsonia florida) grows up to 40 feet with large drooping branches and a round crown. It is spiny, green, multi-trunked, and deciduous. The twigs and young branches are bluish-green, as are the leaves, which are larger than the foothill yellow or littleleaf palo verde (Parkinsonia aculeata). Both have twice pinnate leaves (leaves with two stems and opposing leaflets on each stem), with the foothill species having more abundant leaves growing on longer stems. The blue palo verde blooms in March and April with brilliant bright yellow flowers of 5 petals; the banner petal showing red-orange spots. Pods contain from one to eight seeds, with one being far more common than eight. The blue palo verde species grows primarily in washes and occurs principally in fine soils. Blue palo verdes live 30-50 years. During their short flowering season, the trees are covered with thousands of five-petaled yellow blossoms. Palo Verde is Spanish for green wood or stick alluding to the plant’s greenish branches and trunk.

The Peach (Prunus persica) is a deciduous tree native to the region of Northwest China between the Tarim Basin and the north slopes of the Kunlun Shan mountains, where it was first domesticated and cultivated. The word persica refers to its widespread cultivation in Persia, where it was transplanted to Europe. It belongs to the genus Prunus which includes the cherry, apricot, almond and plum, in the rose family. Prunus persica grows to 13–33 ft tall and 6 inches in diameter. The leaves are lanceolate, 2.8–6.3 inches long, 0.79–1.18 inches broad, pinnately veined. The flowers are produced in early spring before the leaves, are solitary or paired, 1–1.2 inches in diameter, pink, with five petals. Peaches will grow in USDA zones 4 to 8. These photos were taken on the Barnhardt Canyon Trail March 2, 2016 at or near zone 8b which is 15 to 20 degrees minimum. It would be interesting to know how it got there.

Interestingly, peach and nectarines are the same species, even though they are regarded commercially as different fruits. In contrast to peaches, whose fruits present the characteristic fuzz on the skin, nectarines are characterized by the absence of fruit-skin trichomes (fuzz-less fruit); genetic studies suggest nectarines are produced due to a recessive allele, whereas peaches are produced from a dominant allele for fuzzy skin.