May
22

AZ wildfire updates as of 21May2012

Well … it’s that time of year in the southwest again (and I apologize for the lack of posts and updates).

There are several wildfires burning around Arizona and the following updates are as of late 21-May-2012:

Sunflower Fire – began May 12, 2012 about 30 miles north of Mesa, AZ and 21 miles south of Payson near Sunflower in Tonto National Forest.

  • Size: 16,115 acres / Fuels: grass, chaparral, pinyon pine, dense Arizona cypress trees in the southwest corner. Terrain is extremely difficult and dangerous for the 264 fire personnel on the front lines.
  • Currently is 43% contained / Estimated containment: July 30th
  • So far there are no evacuations but parts of Tonto National Forest are closed. For more information regarding forest recreation sites and fire restrictions, contact the Tonto National Forest at (602) 225-5200, or visit www.fs.usda.gov/tonto, or www.fs.usda.gov/asnf/.

Gladiator Fire – reported May 13 near community of Crown King. The human caused fire which originated from a structure fire on private property has now moved onto the Prescott National Forest.

  • Size: 14,693 acres / Fuels: Ponderosa pine and chaparral. Steep terrain and limited access for the 1,160 personnel
  • Currently only 19% contained
  • An expanded Closure Order is in effect, as of May 20, 2012 at 6 p.m., for all Prescott National Forest and parts of Bradshaw Ranger District land.  The public can obtain fire information from Gladiator Fire Information: 928-632-4368 or 928-632-4420 (7am to 10pm) / Prescott National Forest Fire Information Hotline: 928-777-5799 (recorded message) / Gladiator Fire Incident Website: http://www.inciweb.org or http://www.fs.usda.gov/prescott

Bull Flat Fire – began May 10, 2012 in a remote area of the Fort Apache Agency about 20 miles northwest of Cibecue, AZ and is believed to be lightning caused.

  • Burned 2,145 acres of grass, brush and a heavy dead and down component left over from the now 10-year-old Chediski Fire.
  • Currently is 95% contained.
  • The Tonto National Forest Temporary Area Closure for the Bull Flat Fire will remain in effect as posted, until further notice. Both the Tonto National Forest and the Apache-Sitgreaves National Forest have implemented Stage 1 Fire Restrictions. For more information regarding forest recreation sites and fire restrictions, please contact the Tonto National Forest at (602) 225-5200, or check online at www.fs.usda.gov/tonto, or www.fs.usda.gov/asnf/.

Some other contained  and small fires per Inciweb…

  • School Canyon Fire (near Tubac / about 7,049 acres with 100% containment)
  • Collins Fire (started May 21, 2012 / Location is along Highway 83, Mile Marker 6, approx 3 miles north of Parker Canyon Lake. Approximately 50 acres burning in grass and brush but firefighters are making good progress on containment. Parker Canyon Lake is closed at this time.)
  • Campini Fire (west of Montezuma Pass along the Mexican Border. The fire started in Mexico, and has entered the Coronado National Forest. No structures are threatened but it just started and very small so hopefully contained soon.)

The coming monsoon and possible Pacific hurricane moisture will eventually bring much needed rain and higher humidity, but sadly those also bring lightning to a bone dry desert so more wildfires to come.

Also keep in mind… since the long weekend is coming up, many people (esp visitors) across AZ will be hiking and picnicking in our parks and backcountry so please, PLEASE be careful with cigarettes, off-road vehicles (which can sometimes spark), grills and camp fires..!

Some Wildfire Resources:

AZ Emergency Information Network Emergency Bulletins www.azein.gov

Southwest Coordination Center – updates on AZ and NM wildfire incidents http://gacc.nifc.gov/swcc/information/information.htm

Arizona Interagency Wildfire Prevention – news, safety tips, etc http://wildlandfire.az.gov/links.asp

Ready Set Go  http://wildlandfirersg.org/

For statewide road conditions and closures visit www.az511.gov or dial 5-1-1 from any landline or mobile phone from anywhere in Arizona.  (From outside Arizona, dial 1-888-411-ROAD (7623) or 602-523-0244)

And for those of you living in fire country … check out some Wildfire safety tips on APN forum

Stay safe out there, itsa

May
17

Southern Arizona prepper in the news

KVOA ran a good segment last night of a Tucson prepper with a great message. Check out the video below and read the full story on KVOA. (Thank you Avery!)

Also learn more about the Southern Arizona Preppers meetup group here … and find more meetups around Arizona in the AZPN forum.

May
12

1st Annual ARIZONA SURVIVALIST SHOW (May 19, 2012 in Mesa)

If you are in the Mesa area (part of Phoenix metro) next Saturday May 19th, 2012 consider attending the 1st ANNUAL ARIZONA SURVIVALIST SHOW from 9AM-3PM.

According to show organizer Lance Baker, this a fund raiser for the “all volunteer” Commemorative Air Force Museum at Falcon Field in Mesa. An incredible museum with many WWII era aircraft, 90% of which fly. So, for the price of admission, you get to support and see the many incredible aircraft at the museum, plus you will be partakers of the first ever of its kind — THE 1st ANNUAL ARIZONA SURVIVALIST SHOW !!!

Check out the museum’s website: http://www.azcaf.org/

There will be many Arizona based vendors selling related products, with several already slated to do mini-seminars regarding canning, food storage, product demos, and other sessions.

Learn more, download the flyer and join in on the conversation in the AZPN forum

May
06

The Old Man and the Totem Pole

by - Tucson Citizen (June 16, 2010) Our thanks to Mr DuHamel for his permission to share his series. This is the last of his older posts on various desert plants, but we’ll share more of his informational and educational articles in the coming weeks and months.

This is the tale of two cacti, the Senita (also known as the Old Man Cactus) and the Totem Pole cactus. You see both around town. They are intimately related and share the same scientific name, but look very different from each other.

The Senita looks very similar to the Organ Pipe cactus, but the senita has a dense cluster of spines near the top of mature branches. See photos below for comparison, Senita on left.

  

The spines on the senita look like whiskers, hence the name “Old Man.” Only the mature branches have the spine cluster. The senita is far more frost tolerant than the organ pipe, allowing it to survive farther north and to higher elevations. Senitas can grow to 13 feet tall. Pink, nocturnal flowers about an inch in diameter emerge through the bristles from April through August. The flowers have an unpleasant odor. They are followed by marble-sized red fruits with juicy red pulp. Native people ground the seeds of the fruit into a nutritious mush, and the pulp was boiled down to syrup.

 

Senitas are pollinated by a moth that lives among the spines. The moth larvae survive by eating the developing fruit. This example of mutualism is similar to that of certain yuccas and their pollinating moths.

Senitas are long-lived cacti. According to an ASDM report: “When sites in Baja California photographed in 1905 were revisited in the 1990s, nearly every senita was still present.” The natural range is from extreme southern Arizona, to Sonora, and Baja California.

The totem pole is a spineless, bumpy cactus that developed as a natural mutation from the senita cactus. It grows naturally only in a small area of Baja California.

All the totem pole cacti in a population are a single clone; it rarely flowers and cannot produce fertile seeds.

It can reproduce by “pupping” from roots, and you can grow new plants simply by placing a cut branch in soil. They are often used as landscaping plants. Some horticulturists warn not to touch the cactus with bare hands because skin oils will damage the cactus.

Both senitas and totem pole cactus share the genus and species name Lophocoreus schottii (aka Pachycereus schottii). A subspecies name of monstrosus is added to the totem pole cactus in some classifications.

Copyrighted by Jonathan DuHamel. Reprint is permitted per Mr. DuHamel and per his original post on Tucson Citizen

See also:

Ocotillos and the Boojum

Desert Tobacco, a pretty but poisonous desert plant

Palo Verde trees will turn  the desert golden

Jojoba oil, good on the outside, bad on the inside

Saguaro Cactus Icon of the Sonoran Desert

Chiltepin peppers, spice and medicine

The Creosote Bush, a Desert Survivor

Can You Get Potable Water From a Cactus?

Mesquite Trees provide food and a pharmacy  and  More on Mesquite

Brittlebush and chewing gum

Yuccas provide food, fiber and soap

Edible Desert Plants – Barrel Cactus fruit

Agave has many uses

Also join in on the discussions on these posts (and more) in the Arizona Preppers Network forum

Apr
28

Ocotillos and the Boojum

by - Tucson Citizen (October 28, 2011) Our thanks to Mr DuHamel for his permission to share his series.

For most of the year, the ocotillo (Fouquieria splendens) looks like a spiky, dead stick, but come rain and it leafs out profusely.  The ocotillo family consists of 13 species confined to the warm and arid regions of North America.

The ocotillo common to Arizona and Sonora can leaf out completely within 48 hours of a rainfall.  If there is no additional rain, the leaves turn yellow and fall off within a few weeks.  This cycle can be repeated many times during the year.  When the leaf falls off, the petioles (leaf stalks) harden to form spines.

The ocotillo is classified as a woody shrub that can get up to 20 feet high.  It flowers in the spring whether or not it has leaves.  The bright red to red-orange flowers are pollinated primarily by hummingbirds, but also by insects such as carpenter bees.  Ocotillo flowers are frequently the only abundant flower in dry years.

The flowers, when soaked in cold water make a refreshing drink, and the flowers can be used to garnish salads.  They usually have a slightly sour taste like lemon.  Ocotillo stems are used for house walls, ramada roofs, and fences.  Ocotillo stems often take root creating a living fence.

If you look closely at the second photo, you may see that parts of the stem are green.  This allows the plant to carry on photosynthesis even when leafless.  Ocotillos also have the ability to idle their metabolism to survive long periods of drought.

Ocotillos grow from low elevations up to about 6,000 feet.  At higher elevations they prefer to grow on limestone, a fact valuable to geologists.  The reason for the limestone preference is that limestone has a higher specific heat than other rocks and thus offers more frost protection to the plant.  At hotter, lower elevations, ocotillos grow better in granite because granite weathers into a gravelly soil that retains moisture.

The boojum (Fouquieria columnaris) is a relative of the ocotillo.  Boojums are endemic to Baja California and can grow up to 60 feet high.  Unlike the ocotillo, the boojum is a succulent. The stem stores water.  The stem produces hundreds of non-succulent branches that have spines.  Leaves sprout any time moisture is available.

Boojums generally grow in winter and sprout fragrant flowers.  The plants can live up to 100 years.

Boojums are pollinated by insects, but it seems that different insect species do the pollination in different years.

According to the Arizona-Sonora Desert Museum, the boojum got its name as follows:

“The English vernacular name comes from Lewis Carroll’s The Hunting of the Snark, a fictitious account of exploration of far-away places. The book contains a mythical creature called the “boojum” which inhabited distant shores. When explorer Godfrey Sykes encountered the plants growing on the desolate Sonoran coast in 1922, he was reminded of Carroll’s story and dubbed them boojums.”

Ocotillo-like plants grow in Madagascar, but these are in a different family, the Didiereaceae.  These plants grow much larger and have succulent leaves.  That they look like ocotillos is an example of convergent evolution, structure follows environmental conditions.

Copyrighted by Jonathan DuHamel. Reprint is permitted per Mr. DuHamel and per his original post on Tucson Citizen

See also:

Desert Tobacco, a pretty but poisonous desert plant

Palo Verde trees will turn  the desert golden

Jojoba oil, good on the outside, bad on the inside

Saguaro Cactus Icon of the Sonoran Desert

Chiltepin peppers, spice and medicine

The Creosote Bush, a Desert Survivor

Can You Get Potable Water From a Cactus?

Mesquite Trees provide food and a pharmacy  and  More on Mesquite

Brittlebush and chewing gum

Yuccas provide food, fiber and soap

Edible Desert Plants – Barrel Cactus fruit

Agave has many uses

Also join in on the discussions on these posts (and more) in the Arizona Preppers Network forum

Apr
21

Desert Tobacco, a pretty but poisonous desert plant

by - Tucson Citizen (April 24, 2010) Our thanks to Mr DuHamel for his permission to share his series.

The winter rains have caused many perennial plants to bloom this spring. Among those blooming in my yard is Desert Tobacco (Nicotiana trigonophylla, aka Nicotiana obtusifolia). This bush-like plant gets up to three feet high and blossoms with trumpet-shaped greenish-white to pale yellow flowers. The large leaves are oblong, green, and clasp the stem. The seed capsules contain many small brown seeds. The entire plant is sticky and covered with small hairs.

Desert tobacco can be found throughout the Southwest at elevations below 5,000 feet. It favors disturbed ground and desert washes.

This plant is in the Solanaceae (Nightshade) family, a family which contains some very poisonous plants such as Deadly Nightshade and Sacred Datura. The family also includes potatoes, tomatoes, and chili peppers.

As the scientific name implies, the plant contains nicotine and other alkaloids such as anabasine. These alkaloids can be poisonous in sufficient dosage. The USDA estimates the LD50 dose (lethal to 50% in rats) is 11 mg/kg for anabasine and 50 mg/kg for nicotine. According to An Illustrated Guide to Arizona Weeds, from The University of Arizona Press, the leaves and young stems are the most poisonous parts. Desert Tobacco is poisonous to all kinds of livestock and to humans; cattle and horses are poisoned more often than sheep under normal range conditions. The minimum lethal dose of desert tobacco is about 2 percent of the animal’s weight on a green weight basis.

In spite of the possibly poisonous nature, or maybe because of its qualities, the plant has been used for pleasure, ceremonies, and medicine by native people. According to the National Park Service, leaves were chewed, smoked, or used in a drinkable decoction as part of rituals in many groups, such as to control rain, increase crop production, divining and improve health of community, to drive away malevolent powers. It was smoked by travelers to clear away all danger and ensure blessing from spiritual guides. A poultice was applied to cuts, bruises, swellings and other wounds. An infusion was used as an emetic. Leaf smoke blown into the ear and covered with a warm pad treated earaches.

I’ve seen this plant promoted by nurseries as a landscaping option.

As the seed pods develop, you may see the plants covered with small dark bugs in the family Thyreocoridae. They feed on the developing seeds.

Copyrighted by Jonathan DuHamel. Reprint is permitted per Mr. DuHamel and per his original post on Tucson Citizen

See also:

Palo Verde trees will turn  the desert golden

Jojoba oil, good on the outside, bad on the inside

Saguaro Cactus Icon of the Sonoran Desert

Chiltepin peppers, spice and medicine

The Creosote Bush, a Desert Survivor

Can You Get Potable Water From a Cactus?

Mesquite Trees provide food and a pharmacy  and  More on Mesquite

Brittlebush and chewing gum

Yuccas provide food, fiber and soap

Edible Desert Plants – Barrel Cactus fruit

Agave has many uses

Also join in on the discussions on these posts (and more) in the Arizona Preppers Network forum

Apr
14

Palo Verde Trees Will Turn the Desert Golden

by - Tucson Citizen (April 12, 2010)

During the next two or three weeks, the palo verde trees will bloom and make the desert golden. Once pollinated, the yellow flowers will produce edible beans.

There are four species of green-barked trees: the Blue palo verde (Parkinsonia floridum), the Foothills palo verde (Parkinsonia mycrophyllum), the Mexican palo verde (Parkinsonia arculeata), and the Palo brea, (Parkinsonia praecox). In older texts the genus name is Circidium for all four species.

The Blue and Foothills palo verdes are considered native to southern Arizona; the Mexican palo verde inhabits the border region with Mexico, but there are plenty of them in the Tucson area, probably initially introduced. The Palo brea is native to central Sonora, Mexico, but it is used for landscaping, especially in Phoenix (watch out for the low-hanging spiny branches). All of these trees are drought deciduous which means they are leafless in dry times. Chlorophyll in the bark enables them to carry out photosynthesis even while leafless.

The first to bloom will be the Blue palo verdes. They tend to inhabit dry washes because they need just a little more water than the Foothills variety. The Blues are multi-branched trees that can grow up to 40 feet high. The branches tend to droop. The bark, especially young bark, is bluish-green. The leaves are twice-pinnate with leaves about one-quarter inch long and occur as two to four leaves along the two pinnae (feather-like stalks or veins). These trees stop growing after about 30 years and may die long before reaching 100.

The Foothills palo verdes will bloom about two weeks later than the Blues. They tend to have straight upright branches with a yellowish-green color. The trees are usually about 15 feet high but can get up to 40 feet. The leaves are also twice pinnate, about one-tenth of an inch long with about three to five pairs of leaves along two pinnae. The life span is 100 years or more.

The Mexican palo verdes bloom as the Foothills are finishing and can bloom through August. The Mexican palo verde also have upright branches, but have drooping long pinnae which hold tiny leaves. The trees are very fast growing (up to 8 feet per year) and can get up to 40 feet high. Leaves are about the same size as the Foothills and consist of 10 to 40 pairs along the pinnae which can be up to a foot long. The life span is about 30 years.

Palo breas are small trees (25 feet) like the Foothills, but with leaves similar in size to the Blue palo verde. The green bark is relatively dark and granular.

The yellow flowers of  Palo verde trees are five-petalled. One petal, called the banner petal, stands out above the plane of the other four petals.

In the Blue palo verde, the banner petal is yellow and sometimes has orange spots.

The Foothills palo verde has a white banner petal.

The Mexican palo verde may have a yellow to red banner petal or it may have red or orange spots.

The Palo brea flowers are similar to those of the Blue palo verde, but form close to the branch making the branches look like yellow rods.

With a little practice, you can learn to identify the trees by the flowers and leaf size. But just to make things interesting, they form hybrids with each other.

The bean pods of the Blue palo verde are flat and the beans resemble small lima beans. They have a slight bitter taste when green. The pods generally contain one or two beans. The pods of the Foothills palo verde contain two to four navy-bean sized beans separated by a very narrow pod neck. These beans are very sweet when picked fresh and eaten raw; the taste is similar to snow peas. The pods of the Mexican palo verde usually contain three to five beans or more. The beans have a slight bitter taste when raw. After a few weeks, the beans of all three species dry out and become hard. They were often harvested in this condition and later ground into meal.

Palo brea pods resemble those of the Blue palo verde, flat. The Palo brea (tar stick) exudes a waxy substance from its trunk. Native Americans used it for glue.

 

These trees are bee pollinated and you can sometimes see as many as 20 species of bees at the tree at one time. (There are more than 1,000 species of bees in southern Arizona.)

Now for a physics lesson.

Ever wonder why desert plants, especially palo verde trees, have such tiny leaves compared to broad leaf trees such as maples and eastern oaks? That trait is called microphylly and the Foothills palo verde (Parkinsonia mycrophyllum) is the extreme example.

Desert plants must maintain an internal temperature of less than 115 degrees Fahrenheit to survive. The size of their leaves helps them do that. A group of many small leaves has a larger surface area than a single large leaf of equal volume. This large surface area helps the plants lose heat by radiation. Also, in the wind, a large leaf will tend to develop a boundary layer of stagnant air. With small leaves, the boundary layer air does not develop, so the leaves can radiate heat without transpiration, even in relatively calm air.

And, by the way, the Palo Verde is the Arizona State Tree.

Copyrighted by Jonathan DuHamel. Reprint is permitted per Mr. DuHamel and per his original post on Tucson Citizen

Also see:

Jojoba oil, good on the outside, bad on the inside

Saguaro Cactus Icon of the Sonoran Desert

Chiltepin peppers, spice and medicine

The Creosote Bush, a Desert Survivor

Can You Get Potable Water From a Cactus?

Mesquite Trees provide food and a pharmacy  and  More on Mesquite

Brittlebush and chewing gum

Yuccas provide food, fiber and soap

Edible Desert Plants – Barrel Cactus fruit

Agave has many uses

Also join in on the discussions on these posts (and more) in the Arizona Preppers Network forum

Apr
09

Prepper Meetup Groups in Arizona

 

Map of all American Preppers Network and Partner meetup groups.

Scroll past the map for a listing.


View American Preppers Network Meetups in a larger map

Phoenix Area
Glendale

Tucson Area
Tucson Preppers
Southern Arizona Preppers

 

Apr
07

Jojoba oil, good on the outside, bad on the inside

by - Tucson Citizen (April 4, 2011)

Jojoba, (pronounced ho-ho-bah), Simmondsia chinensis, is an evergreen desert shrub that is usually about five feet high and wide, but can grow up to 10 feet tall. There are male and female plants usually with the ratio of four males to every female in Arizona. Only the female plant bears “fruit.” The leaves of both male and female plants are grayish-green, usually just over one inch long and usually stand vertical to the ground.

The vertical leaves are an adaptation to desert heat. Heat slows down photosynthesis, but since the leaves are vertical, they catch the full sun only in the early morning and late evening, but not during the hottest part of the day.

Both male and female jojobas produce flowers. The male flowers are small ball-like greenish yellow clusters. The green female flowers are single. The jojoba is wind-pollinated, and the orientation of the leaves also help create vortexes in the wind which aid in pollination. Flowers appear in winter and the mature seeds develop in spring and summer. Mature seeds in their shell resemble acorns, so they are sometimes called nuts.

Jojobas occur naturally throughout the Sonoran desert where rainfall exceeds five inches per year. They also occur in the coastal ranges of California.

Jojoba is the second most economically valuable native plant of the desert (after Washington palms). The reason is that jojoba seeds contain about 50% ‘oil” which is actually a liquid wax. Because it is a wax rather than an oil, it does not get rancid.

Jojoba “oil” is very similar in properties to sperm whale oil which it has replaced. The “oil” is a high-quality lubricant, can stand temperatures up to 570 degrees F, and is used in many industrial applications especially in computer and other electronic applications. It is also used extensively in cosmetics.

The “oil” itself is odorless, colorless to slightly yellow, and penetrates skin easily, making it a great skin lotion. It also has antifungal and antimicrobial properties. The O’odham Indians use a paste of the seed as an antioxidant salve on burns. The Seri Indians, who were masters of obtaining food in the desert, did not regard the seeds as food, but used it in emergencies as an appetite suppressant. It has a strong laxative effect in humans. According to WebMd, jojoba “oil” is also used effectively for acne, psoriasis, sunburn, and chapped skin. In the early 1700s, it was brought to Spain and promoted as a cure for baldness, but there is no evidence that it works for that purpose.

Jojoba “oil” was used by native people as a cooking oil. Because it is indigestible, it contains no digestible calories. However, there is a debate on internal use of jojoba seeds and “oil” and some medical authorities recommend against internal use. The “oil” contains 14% erucic acid. In high doses, erucic acid is toxic to humans. Drugs.com reports that it has been linked to myocardial fibrosis. (Note: there was a similar concern about canola oil. Originally canola was made from wild rapeseed which contains up to 45% erucic acid, but canola oil is now made from a cultivar that contains less than 2% erucic acid and is deemed safe by the FDA.)

Jojoba foliage is grazed upon by many animals including deer, javelina, bighorn sheep, and livestock. Seeds are eaten by many animals, including squirrels and other rodents, rabbits, and larger birds. However, only Bailey’s pocket mouse is known to be able to digest the wax, according to the Arizona-Sonora Desert Museum.

Jojoba is now grown on farms for commercial purposes. It is relatively expensive because it must be harvested by hand, and the seeds don’t all mature at the same time.

Copyrighted by Jonathan DuHamel. Reprint is permitted per Mr. DuHamel’s original post on Tucson Citizen

Also see:

Saguaro Cactus Icon of the Sonoran Desert

Chiltepin peppers, spice and medicine

The Creosote Bush, a Desert Survivor

Can You Get Potable Water From a Cactus?

Mesquite Trees provide food and a pharmacy  and  More on Mesquite

Brittlebush and chewing gum

Yuccas provide food, fiber and soap

Edible Desert Plants – Barrel Cactus fruit

Agave has many uses

Also join in on the discussions on these posts (and more) in the Arizona Preppers Network forum

Apr
03

Saguaro Cactus Icon of the Sonoran Desert

by - Tucson Citizen (June 23, 2011)

This is the time of year when saguaros bloom and produce fruit. For many generations the Tohono O’odham people have harvested the fruit using long poles made of saguaro ribs. The fruit may be eaten raw or it may be cooked down to a sweet syrup. In the O’odham tradition, some of the syrup was fermented into wine used in a ceremony to herald in the summer monsoon. Dried seeds from the fruit, up to 5,000 per fruit, are rich in protein and fat and can be ground into meal.

Saguaros commonly reach 40 feet tall, a few reach 60 feet to 80 feet. Growth rate depends on rainfall and soil conditions. In Tucson, which averages 12 inches of rain per year, saguaros take about 10 years to get 2 inches high and 30 years to get 2 feet high. Arms may form when the saguaro is 50 to 100 years old and 7 to 12 feet high. Saguaros growing on sandy alluvial fans tend to be bigger and have more arms than plants growing on steep, rocky slopes. The saguaro’s range is restricted almost entirely to southern Arizona and western Sonora. This range is defined by rainfall (too little in the Mojave desert) and by freezing temperatures.

Anatomy

(paraphrased from A Natural History of the Sonoran Desert by Arizona-Sonora Desert Museum press.)

The saguaro (Carnegiea gigantea) is covered by thick, waxy skin that waterproofs the surface and restricts water loss through evapotranspiration almost exclusively to the stomates (pores for gas exchange). The outer surface is folded into pleats (commonly called “ribs,” but not to be confused with the internal, woody ribs. The pleats allow the stem to expand in girth during water uptake without stretching and bursting. Areoles, the roundish pads from which the spines and usually the flowers are produced, are distributed at 1-inch intervals along the ridges of the ribs. Each areole bears a cluster of about 30 spines up to 2 inches long. The spines help protect the plant from herbivorous animals and provide shade to reduce water loss. The lower trunks of old saguaros lose their spines and develop dark, corky bark.

Immediately beneath the skin is a thin layer of chlorophyll-containing tissue where most photosynthesis takes place. The deeper interior, most of the bulk of the plant, consists of the water storage tissue. A fully hydrated saguaro contains 90% water and a large plant weighs about 80 pounds per foot. This water-bearing tissue helps protect the cactus from temperature extremes.

Heat is absorbed through the surface during the day and is stored, resulting in a small temperature rise that does not reach a lethal level. At night, the heat is slowly radiated back into the air. This same thermal inertia usually keeps the tissues above freezing on cold winter nights.

(You cannot tap into a saguaro to get a drink of water. See my post “Can You Get Potable Water From a Cactus?” to find out why.)

A cylinder of 13 to 20 woody ribs occur near the center of the cactus stem, running the length of the main stem and branching into the arms. In the upper part of the stem, the ribs are separate; as the stem ages the ribs continue to grow and fuse into a latticed cylinder. The outside of these woody ribs contain the vascular, or water transporting, part of the plant.

A tap root extends down about 2 feet. The rest of the extensive root system is shallow, rarely more than 4 inches, and radiate outward about as far as the cactus is tall. 

 

Flowers and pollination

Flowers occur near the top of the main stem and on the tips of arms. The white flowers are about 3 inches in diameter and smell like ripe melon. Each flower opens at night and remains open until mid-afternoon the next day. Nectar produced at night attracts bats. A second batch of nectar is produced in the morning to attract birds and insects. Bats and white-winged doves are the main pollinators. The doves, Gila Woodpeckers, and House finches disperse the seeds.

After the flowers are pollinated and fruits mature, the fruit opens to expose its red interior leading some people to think there are red flowers atop the saguaro.

 

  The Boots

Many large saguaros contain holes excavated by Gila Woodpeckers and Gilded Flickers. The birds go in and down, removing the fleshy part of the cactus. The cactus produces scar tissue, calus, which quickly becomes very hard and impervious to bacterial infection. This material, often in the rough shape of a boot, survives after the cactus dies and rots away. Woodpeckers generally excavate a new hole each year, leaving the hole for other cavity-nesting birds.

 

Mortality

Most saguaro seedling die from drought, frost, and predation. Seedlings up to a foot tall are eaten by rodents and rabbits.

Some mature saguaros are killed by lightening strikes or blown over by high winds. However, the chief agent of mortality in the Arizona Upland is freezing. Mortality by freezing depends of the seasonal timing and duration. A healthy middle-aged saguaro can stand a few hours of temperatures as low as 10 degrees F in mid-winter. On the other hand, 12 hours of 20 degrees F in late fall causes damage and death.

According to Natural History cited above, a frost-damaged saguaro may survive for another decade or longer, but eventually weakens until it can no longer resist infection. “Bacterial rot caused by Erwinia cacticida turns the flesh of weakened plants into an odoriferous black liquid.” Healthy saguaros can ward off small infections by walling off infected parts. The bacterium is carried by a moth whose maggot-like caterpillar burrows into the cactus and feeds on the rot it introduces. Many living saguaros have round, half-inch scabs on their surface. These are the caps of contorted tunnels left behind by the caterpillar.

Back in the 1990′s some biologists published a paper about the “brown decline” and impeding doom of saguaros. These scientists were unfamiliar with saguaro biology. There was a great freeze in December, 1978, which affected some of the old saguaros and this is what the visiting biologists focused on. They ignored the large population of smaller, younger saguaros.

Copyrighted by Jonathan DuHamel. Reprint is permitted per Mr. DuHamel’s original post on Tucson Citizen

Also see:

Chiltepin peppers, spice and medicine

The Creosote Bush, a Desert Survivor

Can You Get Potable Water From a Cactus?

Mesquite Trees provide food and a pharmacy  and  More on Mesquite

Brittlebush and chewing gum

Yuccas provide food, fiber and soap

Edible Desert Plants – Barrel Cactus fruit

Agave has many uses

Also join in on the discussions on these posts (and more) in the Arizona Preppers Network forum

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