Vegetation Key

Included here are a key to common desert plants that are found in the Sonoran desert and may be used in "desert landscaping" and a list with description of common ornamental plants. Most of the plants are linked to herbarium samples from the ASU Vascular Plant Herbarium (http://lsvl.la.asu.edu/herbarium/) to help you in identifying your samples. Please Note: Names that are linked will open into a new browser window.

You may wish to create your own "key" for plants around your schoolyard as they may be a combination of ornamental and desert plants. You might wish to contact local landscape architects or nurseries for help in identifying your plants.

	Opuntia basilaris (Beavertail cactus). Plants without spines.
	Opuntia chlorotica (Pancake prickly pear). All of the long spines on the flat surface of the stems point downward. most stems are more round than oblong. Spines 2-4 cm. long.
	Opuntia engelmannii (Engelmann's prickly pear). Joints can be more than 25 cm. long. Joints more oblong than round. Spines 2-4 cm long. Usually does not grow close to ground. Spines equally distributed between top and bottom halves of joints.
	Opuntia phaeacantha (Brown-spined prickly pear or Sprawling prickly pear). Joints 15-25 cm. long. Joints more oblong than round. Spines 5-6 cm long. Most of longer spines are on top half of joints. Grows close to ground.

Carnegiea gigantea (Saguaro). Vertical ribs. Stem is much taller than wide (at least 10 times). Very massive. One main trunk with the possibility of several branches high up on the trunk.

Echinocereus engelmannii (Engelmann's hedgehog cactus). Verical ribs. Plant small. Usually less than 0.5m high. Stems single jointed. Grows vertically. Plant looks very spiny.

Barrel cactus (Large plant (0.5-3 m. high). Can be almost as wide as tall. Barrel shaped. Vertical ribs).

	Opuntia acanthocarpa (Buckhorn cholla). End joints 2 cm or more in diameter. Joints do not fall off and there are no joints scattered under plants.
	Opuntia arbuscula (Pencil cholla). End joints 7-10 mm. in diameter.
	Opuntia bigelovii (Teddy bear cholla). Fruits do not grow in chains. End joints short and very easily dislodged. May be joints scattered around underneath plant. Can be up to 6 feet tall (~1.8m).
	Opuntia fulgida (Chain fruit cholla) Fruits grow in chains. End joints longer and may be dislodged but not as easily. Can be up to 12 feet tall (~3.6m).
	Opuntia leptocaulis (Desert Christmas cactus). End joints 3-5 mm. in diameter and 2.5-7.5 mm. long. Plant less than 1 m. high. May have red fruit.

Mammillaria grahamii (Arizona fishhook cactus). Verical ribs. Small round cactus. Spines are hooked (like a fishhook).

Ocotillo (Not actually a cactus but may be confused as one. Actually a shrub)

Fouquieria splendens (Ocotillo): Up to 6 m. tall, vertical branches joining at ground. many spines along branches. Leaves green, oval, up to 5 cm. long. Most of the year canes are leafless

Species Description

Acacia greggii (Cat-claw acacia):

Spines very curved

Cercidium floridum (Blue palo verde):

Bark/branches blue-green. leaflets 4-8 cm long. usually 3 or less pairs of leaflets per stem.

Cercidium microphyllum (Foothills palo verde): Bark/branches yellow-green. Leaflets very tiny (3 mm. long or less). Usually 4 to 8 pairs of leaflets per stem

Olneya tesota (Iron wood): Medium sized tree, up to 9 m. tall. Trunk up to 45 cm. in diameter. leaflets and bark grayish. Bark may be stringy. Spines not yellow and may be slightly curved.

Parkinsonia aculeata (Mexican palo verde): Bark and/or young branches yellow/green. Main leaf stems flattened and 10 cm. long or longer. Leaflets alternate. Spines in clusters of 3.

Prosopis velutina (Velvet Mesquite): Small tree, up to 3 m. tall. Leaflets and bark not gray, spines yellowish, not curved. Bark not stringy. Branches grow in a zig-zag pattern.

Characteristic
Leaves absent or obscure.		Go to II
Leaves linear, sides parallel (like a blade of grass).		Go to III
Leaves triangular (deltoid).		Go to IV
Everything else.		Go to V

III.

Characteristic
Leaves hairy	Go to A
Leaves not hairy	Go to B

A
Species	Description
Hymenoclea salsola (burro brush, cheeseweed):	Leaves dark green, very slender, lower leaves have 3 or more threadlike divisions, up to 7.6 cm. long. Foliage has cheesy odor when crushed.

B
Species	Description
Atriplex canescens (four-wing saltbush):	Up to 2.5 m. but mostly 1.2 m. Leaves gray-green, narrow, up to 5 cm. long.
Baccharis salicifolia (seep willow):	Up to 3.5 m. high. Leaves dark green, shiny, waxy, sticky, lance-shaped, toothed, up to 15 cm. long and 12 mm. wide.
Baccharis sarothroides (desert broom):	Up to 3 m. tall. Leaves bright green, smooth, sticky, up to 4 cm. long and 3 mm. wide. Growth resembles a broom.
Bebbia juncea (chuckwalla's delight):	Up to 1.2 m. tall. Leaves (when present) dark green, sparse, linear to lance shaped, lobed, rough, hairy, up to 5 cm. long.
Gutierrezia sarothrae (broom snakeweed):	Up to 1.2 m. tall. Leaves dark green, very narrow, up to 3 mm. wide and 6.4 cm. long.

IV.

Species	Description
Ambrosia deltoidea (triangle bursage):	Up to 1.2 m. tall. Leaves gray-green above, white and hairy underneath, finely toothed, up to 3 cm. long
Viguiera parishii (parish viguiera):	Up to 1.2 m. tall. Leaves dark green, hairy, toothed, crinkled, up to 4 cm. long. Grayish bark

Characteristic
Leaves serrate (toothed) or divided/compound AND hairy	Go to A
Leaves serrate (toothed) or divided/compound and NOT hairy	Go to B
Leaves simple and entire (not toothed) AND hairy	Go to C
Leaves simple and entire (not toothed) and NOT hairy	Go to D

A
Species	Description
Ambrosia ambrosioides (canyon ragweed):	Up to 1 m. tall. Leaves green, hairy, elongated to lance shaped, toothed, up to 12.7 cm. long and 2.5 cm. wide.
Hibiscus denudatus (rock hibiscus):	Up to 1 m. long. Leaves yellow-green, densely hairy, oval to elliptical shaped, toothed, and up to 3 cm. long.
Hyptis emoryi (desert lavender):	Up to 4.5m. tall. Leaves gray-green, oval shaped, hairy, toothed, up to 6 cm. long.

B
Species	Description
Celtis pallida (Desert Hackberry):	Up to 6 m. tall. Leaves dark green, elliptical to oval, toothed or untoothed, up to 4 cm. long and 19 mm. wide.
Trixis californica (trixis):	Up to 1 m. tall. Leaves dark green, lance shaped, smooth edge or toothed, up to 5 cm. long and 12 mm. wide.

C
Species	Description
Encelia farinosa (brittlebush):	Up to 1.2 m. tall. Leaves greenish gray and hairy, oblong or triangular shaped up to 10 cm. long.

D
Species	Description
Atriplex polycarpa (little leaf saltbush):	Resembles Atriplex canescens (see part III, B) but leaves are small.
Celtis pallida (desert hackberry):	Up to 6 m. tall. Leaves dark green, elliptical to oval, toothed or untoothed, up to 3 cm. long and 19 mm. wide.
Larrea tridentata (creosote bush):	Up to 3 m. tall. Leaves dark green to yellow-green, waxy, resinous, 2 leaflets joined at base, up to 10 mm. long. Strongly scented.
Fouquieria splendens (Ocotillo):	Up to 6 m. tall. Leaves green, oval, up to 5 mm. long. Most of the year canes are leafless.
Lycium sp. (Wolf-berry):	Branches usually spiny. Leaves in clusters. Leaves shaped from nearly cylindrical to flat. Leaves fleshy.
Simmondsia chinensis (jojoba):	Up to 3.5 m. tall. Leaves grayish green, leathery, thick, and elliptical, up to 4 cm. long.
Ziziphus obtusifolia:	Spiny branches. Leaves alternate and in clusters. Leaves oblong or eliptical.
Trixis californica (trixis):	Up to 1 m. tall. Leaves dark green, lance-shaped, smooth edged or toothed, up to 5 cm. long and 12.7 mm. wide.

Species Description

Arecastrum romanzoffianum (queen palm):

Arching, bright glossy green leaves, 4-6 m tall. Bark shaggy, leaves drooping.

Brachychiton populneus (bottle tree):

Evergreen. Common name comes from the heavy trunk that is broad at the base and tapers quickly. Simple, smooth margined leaves, they shimmer in the breeze like aspens. Clusters of small, bell-shaped white flowers in May and June, woody fruits.

Callistemon viminalis (bottle brush): Native to Australia. Colorful flowers in dense spikes or round clusters. Lanceolate leaves with no teeth. Usually trimmed to look like a tree.

Chilopsis linearis (desert willow): Long, narrow, 5-13 cm leaves. Flowers trumpet shaped with crimped lobes. Flower color pink, white, rose or lavender. Flowers appear in spring and through fall. Attractive to birds.

Citrus (Lemon, limes, limequates, mandarin oranges, oranges, kumquats, sour-acid oranges, tangelos, tangors, and blood oranges):
Oranges | Lemons Thick leathery leaves with a "wing" on the periole. Flowers 5 petals, white, fragrant. Some varieties can bear fruit twice a year.

Cycas revoluta (Sago palm): 0.5-1 m tall, lacey appearance of a fern, related to conifers, produces cones. Leaves divided into many narrow, leathery, dark glossy green segments.

Eucalyptus (sugar gum, white box):
Eucalyptus camaldulensis | Eucalyptus microtheca | Eucalyptus salubris | Eucalyptus torquata

Most widely planted non-native tree. Over 50 species. Some produce beautiful flowers. Silvery bark that peels in patches and long gray-green leaves are fairly common.

Ficus microcarpa (Indian laurel fig):

Evergreen trees. Long drooping branches thickly clothed with blunt-tipped leathery 5-10 cm long smooth leaves. Light rose to green new leaves, produced almost continuously give the tree a two-tone effect. Light gray bark. Also popular: fiddle leaf fig (leaves shaped like a fiddle), Ficus nintiada (great for wind and noise break, fast growing, looks like Ficus microcarpa, but with sharply pointed leaves).

Fraxinus (Ash):
Fraxinus anomala | Fraxinus velutina
Used as shade, lawn, and patio shelter trees. Leaves are divided into leaflets. Leaves 20-38 cm long. Usually paler beneath. Leaflets can range in number from 5 to 9 and can be smooth or toothed, wide or narrow.

Olea europaea (olive): Tree with bicolor willow-like leathery leaves. Produce fruits with valuable oil. Can withstand heavy pruning, so it is often seen in interesting shapes.

Phoenix dactylifera (date palm): Very tall (up to 24 m) with slender trunk and gray-green waxy leaves. Leaflets stiff and sharp pointed. Natural habit is to clump in several trunks.

Pinus (Pines): Various pine trees are planted around the valley including: sugar pine, ponderose pine, white pine, allepo pine, and Indian longleaf pine.

Thevetia peruviana (yellow oleander): Leaves 7-15 cm inches long, very narrow, with edges rolled under. Leaves are deep green, glossy, with inconspicuous veins. Fragrant flowers bloom any time, yellow to apricot, 5-7.5 cm inches long, tubular shaped.

Vitex agnuscastus (monk´s pepper, chaste tree): Small tree, leaves are divided fan-wise into five to seven narrow 5-15 cm long leaflets that are dark green above, gray beneath. Flowers are 18 cm spikes of lavender blue flowers that appear in the summer and fall.

Washingtonia filifera (California fan palm): Always grows near springs or moist spots. Long-stalked leaves have spines, leaflets are fan shaped.

Species Description

Bougainvillea:
B. spectabilis

Bougainvillea´s vibrant colors come not from its small flowers, but from the three large colored bracts that surround them. This plant can be found in shrub or wall cover/vine form. It has large triangular smooth leaves and spines.

Caesalpinia pulcherrima (red bird of paradise):

Dark green leaves with many long leaflets. Orange-red blooms throughout warm weather.

Calliandra eriophylla (fairy duster, false mesquite): Leaves finely cut into leaflets. Flower clusters show pink or red stamens in puffy balls about 2.5 cm across. Blooms in Feb. or March.

Carissa grandiflora (Natal Plum): Fast-growing, strong, rounding shrub with lustrous, leathery, green, 7.6 cm oval leaves. White fragrant flowers with five-petal star shape, appear throughout the year followed by fruit.

Cassia (senna): Flowers may be yellow, bright yellow, egg-yolk yellow, deep yellow, or gold. Leaves are usually divided into leaflets and different species range from dark green to gray leaves. Feathery Cassia is one of the most common landscape plants; leaves are gray, divided into six to eight needlelike 2.5 cm inch long leaflets.

Hibiscus rosa-sinensis (tropical hibiscus): Evergreen shrub. One of the showiest flowering shrubs. Glossy leaves varies somewhat in size and texture depending on variety. Summer flowers can be single or double ranging from 10-20 cm wide. Colors range from white/red/yellow/apricot/orange.

Leucophyllum frutescens (Texas ranger, Texas sage, White Cloud):

Compact slow-growing, silvery soft leaves with bell-shaped flowers blooming various times of the year (depending on rainfall).

Nerium oleander (oleander):

very common shrub, simple, dark green, leathery glossy, leaves. Flowers 5-7 cm across white/pink/salmon/red. Can be trimmed to look like a tree.

Pittosporum tobira (mock orange): Broad dense shrub or small tree. Leaves leathery, shiny, dark green, rounded at edges with a ridge down the middle vein. Clusters of creamy white flowers form at branch tips in early spring and smell like orange blossoms.

Ruellia (ruellia):
Ruellia brittoniana | Ruellia nudiflora | Ruellia peninsularis Shrub with opposite, toothed, purplish leaves that drop if it becomes too dry. Flaring bell-shaped flowers, usually deep purple.

Tecoma capensis (cape honeysuckle): Leaves divided into many glistening, dark green leaflets. Brilliant orange-red tubular, 5 cm blossoms that grow in compact clusters from October through winter. Can have yellow flowers and lighter green foliage.

Species Description

Dalea greggii (trailing indigo bush):

Fast-growing evergreen shrub with pearl gray foliage. Clusters of tiny purple flowers in spring and early summer. Found as ground cover in many desert landscapes because it tolerates heat and lack of water once established.

Hesperaloe parviflora (hesperaloe):

Makes a dense yucca-like clump of very narrow, sword shaped leaves, 1.22 m long to 2.54 cm wide. Pink to rose red, 3 cm nodding flowers in slim 1-1.2 m high clusters bloom in early summer. Leaves usually have slender thread peeling back at edges which looks like curled up dental floss.

Lantana:
Lantana Montevidensis Fast growing, valued for profuse show of color over long season. Yellow, orange, red, pink, lilac flowers form 2.5-4 cm clusters. Dark green leaves 2.5 cm long with coarsely toothed edges. Grows in vining pattern usually seen as a ground cover.

Myoporum parviflorum (Myoporum): Bright green, 2.5 cm leaves completely cover plant. White summer flowers are followed by purple berries. Does not recover well from foot traffic.

Rosmarinus officinalis (rosemary): Narrow, aromatic leaves, glossy dark green above, grayish white beneath. Small clusters of light lavender blue flowers attract birds and bees. Used frequently for ground or bank covers.