Ironwood Tree

The ironwood tree (Olneya tesota) is found only in the Sonoran Desert below 2,500 feet where freezing temperatures are uncommon. Its habitat is almost an identical match for the Sonoran Desert boundary.

This ironwood tree was found near the Cottonwood entrance to Joshua Tree National Park. The bajada between the I-10 freeway and the Cottonwood Mountains is the only place in that park where the ironwood tree is found. It was photographed in early April.

It has one or more trunks, can get as high as 45 feet and live as long as 800 years. It has lavender to pink flowers in May (the tree below was photographed in Organ Pipe Cactus National Monument in late May),

then by early summer has two-inch pods that mature, each containing one to eight shiny brown seeds that are eaten by many animals. It is one of the hardest and heaviest woods in the world and it is remarkably resistant to rotting.

The trunks can persist up to 1,600 years. This particular dead ironwood tree was found on the bajada below the Eagle Mountains near the Hayfield Road exit of the I-10.

It grows extremely slowly, perhaps due to low rates of photosynthesis that keep it from wasting soil moisture. These slow rates contribute to the density of its heartwood.

The leaf is doubly divided into 4 to 12 pairs of narrowly elliptic leaflets called pinnae.

Each leaf has two to four fingers with paired leaflets down the sides of each.

The leaves usually turn yellow and are shed in April before the trees flower. The flowers bloom on the end of short shoots along the branches.

The flowering period lasts only 10 to 18 days.

During long droughts, the trees slough off leaves, limbs and rootlets to reduce water needs. It creates its own micro-habitat. It serves as a perch and roost for hawks and owls.

It tempers the elements beneath it, creating a habitat with less direct sunlight, lower suface temperature (as much as 15 degrees cooler), more organic matter and higher water availability.

Its canopy is utilized by 150 bird species and 62 reptiles and 64 mammals use it for forage, cover and a birthing ground.

It fosters many young plants that grow beneath it, more than 230 species recorded, creating a wonderful forage source for rabbits, bighorn and other animals. Bighorn sheep, pronghorn antelope and mule deer eat its leaves and doves, quail and rodents eat its seeds.

Fringed Twinevine or Climbing Milkweed

Fringed twinevine or climbing milkweed (Funastrum cynanchoides or also Sarcostemma cynanchoides) is one of my new favorite wildflowers. On April 3rd, while hiking in a wash near Carey's Castle in the Eagle Mountains in the southern portion of Joshua Tree National Park, I came across a bizarre plant that I could not (and still cannot) identify.

I had this post prepared with pictures of that plant. It had flowers that are amazingly like the fringed twinevine.

But the rest of the plant did not fit. Then I took a second hike into the same area two weeks later, on April 17th. While on that hike I came across about four of the actual fringed twinevines.

With all of the reading I'd done on it, I instantly recognized it

and was shocked at how much smaller and how much different this plant is than the one I had been identifying it as. The fringed twinevine is found along washes.

It has flowers in umbrella-like clusters

 with five sepals and five petals fringed with white hairs.

The leaves are green, hairless and variable in shape.

The stems are slender, green and twining.

With a casual glance, there is nothing remarkable about the plant.

But a detailed view opens up an amazingly beautiful world of twisting vines,

spectacularly arranged

and colored flowers.

I still have the mystery of the other plant to solve, but it has cemented a real interest and curiousity in me for this plant.

Creosote Bush

Creosote bush, also known as greasewood (Larrea tridentata)

is found in all four southwestern deserts, from southern Nevada, extreme southwestern Utah, southeastern California, the southern one-third of Arizona, southern New Mexico, into west Texas and south into Mexico. The one above was in Organ Pipe Cactus National Monument and the one below was found near Hayfield Rd. off the I-10 freeway just south of Joshua Tree National Park.

It usually is found in open, species-poor land, but it also is a transitional species in desert grasslands, mesquite woodlands, Joshua tree communities and desert washes. It flowers from February to August

with yellow, twisted petals.

After the flower blooms,

it turns into a small white fuzzy fruit capsule that has five seeds.

The seed capsules can be found on the ground under the bush.

It is one of the most characteristic features of the the hot southwestern desert. It tolerates arid conditions and it competes aggressivley with other plants for water. It has stems projecting from a base.

It is usually less than four feet high, but can get as high as twelve feet when it has lots of water.

The yellow-green leaves conserve water and dissipate heat.

It may lose some of the leaves in extreme drought, but never loses all of them. It is an important source to wildlife. Reptiles and amphibians use it as a food source and perch site and hide and hibernate in burrows under it. Desert tortoises dig their shelters under it where its roots stabilize the soil.

Arizona Lupine

Arizona lupine (Lupinus arizonicus) is very similar to Coulter's lupine.

It is a pea-shaped flower that spirals around a hairy flower spike.

Individual flowers are pink, or pinkish purple,

as opposed to blue in Coulter's lupine, and the flower has a red-spotted, yellow and white banner spot that becomes deep magenta with age

(as opposed to a brown spotted, yellow and white banner spot in Coulter's lupine).

The leaves have 6 to 10 leaflets and the upper surface is hairless, unlike Coulter's lupine which has hair and which has narrower leaflets.

These Arizona lupine were photographed off the I-10 freeway outside of Quartzite, Arizona.

Coulter's Lupine or Mojave Lupine

Coulter's Lupine, Mojave lupine or arroyo lupine (Lupinus sparsiflorus),

has a pea-like flower that spirals around a hairy, upright flower spike.

Individual flowers have a brown-spotted, yellow and white banner spot that becomes magenta-tinged with age.

Petals curve upward and have a hairy fringe.  

The leaves are green and have 7 to 11 linear, narrow leaflets. The upper surfaces of the leaflets are covered in spreading and flat-lying hairs and are hairiest near the margins.

The plant, and particularly the seeds, are poisonous. These were photographed just off the highway in Arizona, somewhere between Buckeye and Gila Bend.

Panamint Catseye or Bristlelobe Cryptantha

Panamint catseye, also known as bristlelobe cryptantha, popcorn flower, narrow leaved cryptantha and narrow leaved forget me not (Cryptantha angustifolia) is one of about 160 species of cryptantha.

It is found east of the Sierra Nevada and in the deserts of Southern California over to Texas and northern Mexico.

White flower buds are held in a tight coil (spiral) at the top of the plant.

The flowers start open from the bottom of the plant and move toward the top. This causes the stem to uncoil.

It blooms from February to March. The leaves are dull green-gray, narrow and hairy. This particular plant was found in Organ Pipe Cactus National Monument in March 2010.