By Gertrud Konings, 2015
Ocotillo Family (Fouquieriaceae)
Other names: Candlewood, Slimwood, Coachwhip, Vine Cactus, Flaming Sword, Devil’s
Walking Stick, and Jacob's Staff. Ocotillo means “little torch” in Mexican Spanish.
Ocotillos are typical components of the landscape in the Desert Southwest of the USA
and northern Mexico. Ocotillo is a woody, thorny 10 to 20 feet (3-6 m) tall shrub with
several slender stems growing out of a root crown. The stems are usually unbranched and
seem to grow rather straight out of the crown, but sometimes they can display a rather
bizarre arrangement.
During the winter and
spring and extreme
drought, the plant
looks dead. However,
soon after a rain (3-5
days) the grey stems
produce bundles of
small, oval leaves in
the axils of the thorns.
The small, thick,
leathery leaves are
quickly shed again
when it becomes dry
again (droughtdeciduous) and this
can happen several
times during the year.
The Ocotillos are the major contributors to
the green look of the desert after heavy
rains.
The conical thorns are believed to be made
by the leaves and grow when leaves are
present. (DesertUSA) They are up to one
inch long. The bark of the stalks produces a
resin and wax that was used in the past for
waxing leather to waterproof it and also as
a varnish. The wax is concentrated around
and at the base of the thorns and gives the
plant a grey and green banding pattern,
which is more obvious in younger plants.
Ocotillo stems grow terminal segments during a growth spurt. These segments are
separated by nodal "seams" that remain visible and can be used for growth
measurements, similar to tree rings in trees. (Killingbeck, ) The stems also produce
nectar-secreting glands (nectaries) to attract insects as protection against herbivores.
Looking like bare thorny grey sticks throughout most of the year, the Ocotillos are nicely
decorated with a brilliant red tip during the early spring (March through June), sometimes
also later in the year after heavy rains.
The flowers are produced in dense clusters of about 10 inches long. The flower petals are
united and form tubes. They are curled back at the tip of the flower. Ocotillo flowers are
crucial for migrating hummingbirds. This is the only reliable desert hummingbird food,
since Ocotillos bloom even in dry years when their stems remain without leaves.
Carpenter bees also feed on Ocotillo flower nectar. They are known to slice the flower
tubes at their bases open to suck out the nectar, which is called “nectar robbing”.
Chihuahuan Desert Education Coalition
A Capenter bee
robbing nectar from a
Yellow Bell (Tecoma
stans) flower is
depicted above and to
the left. On the lower
photo, a drop of nectar
is visible.
Still, both, the hummingbirds and the carpenter bees seem to be effective pollinators of
the Ocotillo, as reported in a study done in the Big Bend area. (Desert Museum). The
flowers are edible “straight or soaked in cold water”.
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In springs with good rains the Ocotillos are green while flowering, in dry years the red
flower tips are very decorative on the grey bare sticks of the plant.
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Though ocotillos look like woody shrubs, they behave like stem-succulents, since they
store water in the center of their stems and have very shallow radiating roots, as do
succulents. But it’s a C3 plant, as are the leaves. This means that it keeps its stomata
(little openings) on its surface open during the day to take in the CO 2 that it needs for
photosynthesis. It photosynthesizes also during the day in the dry season when the waxy
stems are leafless and take over photosynthesis. The green patches on the stem contain
the chloroplasts with the chlorophyll to catch the sun light, but they mainly recycle the
CO2 that is released during respiration.
Ocotillo can even provide fall color to the desert, when late leaves turn yellow and give
the desert a golden shine.
Ocotillos are believed to live for about 60 years, but some estimates are hinting at even to
100-200 years. In the Desert Southwest, they are often used in landscaping and therefore
often over- harvested. Some states have banned their harvest, to protect them from
extinction (Arizona). Extracts of the inner stem tissue are used for medicinal purposes to
enhance blood circulation. Another common use of this shrub is as "living fence", when
they are planted closely next to each other, and to cover patios and walkways, known as
ramada roofs.
Ocotillos are scientifically well studied and even genes of these plants that are expressed
during water stress were identified. (Sánchez, 2014) The University of Texas at Austin,
Texas keeps dried segments in its herbarium for classification purposes. A copy of one
sample is depicted below:
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Chihuahuan Desert Education Coalition
References:
- Department of Agriculture, Plant list
http://plants.usda.gov/about_plants.html
- Desert Museum: https://www.desertmuseum.org/kids/oz/long-factsheets/Ocotillo.php
https://www.desertmuseum.org/books/nhsd_fouquieriaceae.php
- Desert USA http://www.desertusa.com/flora/ocotillo.html#ixzz3aLAIGJNA
- Desert USA, Food chain
http://www.desertusa.com/desert-food-chain/food-chain9.htmlhttp://www.desertusa.com/desert-food-chain/food-chain-9.html
- Encyclopedia of life: Fouquieria splendens – Ocotillo; Details;
http://eol.org/pages/487543/details
- Humphrey R. R. A Study of Idria columnaris and Fouquieria splendens. American
Journal of Botany - AMER J BOT 01/1935; 22(2). DOI: 10.2307/2436008
- Killingbeck, K. T. Tracking Environmental Change with the Desert Shrub Ocotillo
(Fouquieria sp/endens): Prospects and Pitfalls.
http://www.researchgate.net/publication/264843234_Tracking_Environmental_Chan
ge_with_the_Desert_Shrub_Ocotillo_%28Fouquieria_spendens%29_Prospects_and_
Pitfalls
- Lady Bird Johnson Wildflower Center:
http://www.wildflower.org/plants/result.php?id_plant=FOSP2
- Master Gardeners of the University of Arizona Pima County Cooperative Extension;
Fouquieria splendens – Ocotillo:
https://ag.arizona.edu/pima/gardening/aridplants/Fouquieria_splendens.html
- McDonald Charlie. Plant of the Week: Ocotillo (Fouquieria splendens):
http://www.fs.fed.us/wildflowers/plant-of-the-week/fouquieria_splendens.shtml
- New Mexico State University http://aces.nmsu.edu/pes/lowwaterplants/ocotillo.html
- P.S. Nobel, B.R. Zutta. Morphology, ecophysiology, and seedling establishment for
Fouquieria splendens in the northwestern Sonoran Desert. Journal of Arid
Environments 2 (2005) 251–265. DOI: 10.1016/j.jaridenv.2004.11.002
- Pima Community College, Desert Ecology of Tucson, AZ; Ocotillo (Fouquieria
splendens): http://wc.pima.edu/~bfiero/tucsonecology/plants/shrubs_oco.htm
- R. I. M. Sánchez, M. D. P. Crisóstomo Vázquez, M. A. V. Alberto, J. L. M. Sánchez
and E. J. Cardoso. 2015: IDENTIFICATION OF GENES EXPRESSED DURING
WATER STRESS IN FOUQUIERIA SPLENDENS SSP. BREVIFLORA.
International Journal Of Pharmaceutical Sciences and Research. DOI:
10.13040/IJPSR.0975-8232.6(4).1396-00; http://ijpsr.com/bft-article/identificationof-genes-expressed-during-water-stress-in-fouquieria-splendens-ssp-breviflora/
- University of Texas Libraries: Wildflowers of Texas
http://www.lib.utexas.edu/exhibits/wildflowers/detail.php?work_urn=urn%3Autlol%
3Awildflower.txu-herb-dexter-316&work_title=Fouquieria+splendens
- Wikipedia; Nectar robbing: https://en.wikipedia.org/wiki/Nectar_robbing
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Watch on youtube:
Pollinators: Hummingbirds
(Hummingbird feeding on Ocotillo flower:
https://www.youtube.com/watch?v=trDPpqyJ7Dk)
WOOD BEES WORKING FLOWERS, Carpenter bee
https://www.youtube.com/watch?v=pw5QlmW4ALk