FLORA AND FAUNA
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Agave shawii ssp. shawii.
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Agave shawii ssp. shawii in Punta Banda,
Ensenada, Baja California.
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Agave shawii ssp. goldmaniana. Photo: Greg Starr.
Sula Vanderplank, associated researcher at Terra Peninsular, next to an Agave shawii ssp. goldmaniana in the Valle Tranquilo Nature Reserve.
Destruction, modification or restrictions of its habitat are the
main threats that this plant faces every day. Although this happens
at a faster pace in the USA, the industrial and agricultural expansion
on the northwest coast of Baja California has had an exponential
increase in the last years, making it too, a considerable threat to the
species. Sometimes the Agave shawii is used to feed cattle. This
has a very negative impact since these plants are being cut even
before they flower, which normally takes between 20 and 40 years
to do so.
The Agave shawii, of the family Agavaceae, is divided into two
subspecies: Agave shawii ssp. goldmaniana and Agave shawii ssp.
shawii. They can be differentiated according to their areas of distribution: the A. shawii ssp. goldmaniana is a species that belongs to
the desert and grows in the central part of the peninsula, while the
A. shawii ssp. shawii predominates on the coast.
The most robust variety is goldmaniana, which can reach a
height between 9 to 16 ft. Its distribution is concentrated in the central and southern part of the peninsula. Meanwhile the A. shawii ssp.
shawii has a more compact and narrower form, its height reaches
between 6 and 13 ft, and it is distributed along the coast all the way
to the 30th parallel of the North Hemisphere (30°0’N).
It is worth saying that both subspecies are very different from
each other although the differences are almost imperceptible to
the uninitiated eye. Both of them produce red buds that turn into
yellow flowers. Nevertheless, the A. shawii ssp. shawii has a panicle-like inflorescence with between 8 to 14 lateral branches, ovate
leaves and rosette up to 40” in diameter. On the other hand, the A.
shawii ssp. goldmaniana has longer leaves, often more branched
inflorescence with 18 to 25 lateral branches, and rosette up to 59”
in diameter.
The areas of occurrence of these two iconic Agaves meet right
at Terra’s Valle Tranquilo reserve, near El Rosario at the southern
limit of the California Floristic Province.
References
• Riley J., Rebman J., Vanderplank S.E. (2015). Plant Guide:
Maritime Succulent Scrub Region, Northwest Baja California,
Mexico. Forth Worth, Texas: Botanical Research Institute of
Texas Press.
• Gentry H.S. (1982). Agaves of Continental North America.
Tucson: University of Arizona Press.
• Turner R. M., Bowers J. B., Burgess T. L. (2005). Sonoran
Desert Pants: An Ecological Atlas. Tucson: University of Arizona Press.
• Webb, Robert H., Starr, G. (2015). Gentry Revisited: The Agaves of Baja California, Mexico. [Electronic version]. Haseltonia, 20, 64–108.
• Vanderplank S. E. (2014). A conservation plan for Agave
shawii ssp. shawii (Shaw’s agave, Agavaceae). [Electronic
version]. Rancho Santa Ana Botanic Garden Occasional Publications, 14.
• Meyer, E., Simancas, J., Jensen, N. (2016). Conservation at
California’s Edge. [Electronic version]. Freemontia Journal of
the California Native Plant Society, 44 (1), 8-15.
• Lauri, B. (2000). Agave shawii ssp. Goldmaniana de Oasis
Marino, Guía de Campo. Obtenida el 4 de marzo de 2016,
de http://sdnhm.org/oceanoasis/fieldguide/agav-sha-sp.html
• Foto Agave shawii ssp. Goldmaniana de Starr G. Obtenida el 11 de marzo de 2016, de http://www.tucsoncactus.org/
html/2015_September_meeting.html
APRIL 2016
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