On the Pleasures (and Perils) of Captive Boojums
by Jay Vannini
Young mature boojums, Fouquieria columnaris, at the Desert Botanical Garden, Phoenix, Arizona.
“For, although common Snarks do no manner of harm,
Yet, I feel it my duty to say,
Some are Boojums - The Bellman broke off in alarm
For the Baker had fainted away…
….But, oh beamish nephew, beware of the day,
If your Snark be a Boojum! For then
You will softly and suddenly vanish away,
And never be met with again!”…
No serious collection of fantastical succulents lacks a boojum. Strictly speaking, a “boojum” in horticulture is the common English language name for Fouquieria columnaris (Fouquieriaceae), a bizarre-looking succulent tree native to central Baja California, some Gulf of California islands and a single northern Sonoran coastal range. However, it can also be used for two other caudex forming tree ocotillo species from southeastern México, F. fasciculata and F. purpusii. Together, they make up a trio of some of the oddest-looking arborescent succulents of all.
Trunk detail of a mature boojum, Fouquieria columnaris at the Desert Botanical Garden, Phoenix, Arizona.
…”It’s a Snark!” was the sound that first came to their ears,
And seemed almost too good to be true.
Then followed a torrent of laughter and cheers:
Then the ominous word, “It’s a Boo-”
Then, silence. Some fancied they heard in the air
A weary and wandering sigh
That sounded like “-jum!” but the others declare
It was only a breeze that went by…”
Lewis Carroll, “The Hunting of the Snark” (1876)
A nice pair of mature cultivated boojums, Fouquieria columnaris, at the Boyce Thompson Arboretum, Superior, Aizona.
The Fouquieriaceae is a family of 11 species of spiny, semi succulent or succulent shrubs and trees mostly endemic (some narrowly so) to México with one widespread species also occurring throughout desert regions of the U.S. southwest and another ranging southeast from Jalisco discontinuously to the Isthmus of Tehuatepec and on to the Chiapan-Guatemalan border (Henrickson 1972; pers. obs.). They are conspicuous inhabitants of Mexican arid and dry forest ecosystems and, in some regions across their range, plants from this family may be a dominant landscape feature (e.g. Fouquieria formosa in the Tehuacán Valley in Puebla and Oaxaca and F. splendens in southeastern California, southern Arizona and northern Sonora). Two or three species may occur in sympatry or in relative proximity, but these species generally partition habitat according to soil preferences. In central and southern Arizona and throughout most of México they are commonly associated with a wide variety of genera of large columnar cacti and artsy images of Sonoran Desert and Mexican Tropical Dry Forest inevitably show these plants together.
Unlike their endemic Malagasy parallels in the Didieraceae (sometimes known as Madagascan ocotillos), which show affinities with cacti, the Fouquieriaceae has no particularly close relatives although it is usually placed alongside the phloxes (Polemoniaceae; Stevens 2008) as part of the Ericales.
Alluaudia ascendens (Didieriaceae) is the most popular “Madagascan ocotillo” species in cultivation. Also known as lemur ladders or fantsiolotse, this is a very fast growing tropical dry forest tree that adapts to a wide range of cultural conditions. The image shows the tops of some ~12’/3.70 m stems growing in my collection in Guatemala. While not related to true ocotillos, several members of the Didieraceae are widely grown by succulent enthusiasts in the U.S. and EU.
The genus was named by Karl Kunth in 1823 to honor Dr. Pierre Fouquier, physician to the courts of Charles X and Louis-Philippe of France. The holotype for the genus, the southeastern Mexican Fouquieria formosa, was collected by Aimé Bonpland and Alexander von Humboldt in 1803.
Common names for individual species in English and Spanish include boojum, ocotillo, candlewood, albarda, cirio, palo Adán, palo santo, rabo de iguana, cascabelillo, torotillo, and árbol de barril.
Lewis Carroll’s cleverly worded nonsense poem - “The Hunting of the Snark - An Agony in 8 Fits” - is the origin of the word “boojum”. The poem is often viewed as an allegory on the pitfalls that sometimes await searchers, specifically those seeking happiness, scientific knowledge, spiritual revelations, etc. Yet, other than it being made clear that, of the two, snarks are more common but still wily and elusive beings and that boojums are rather rare and very dangerous, their true forms were intentionally left enigmatic. This leaves readers free to draw their own conclusions as to what they are meant to represent and adds a great deal of charm to “The Hunting of the Snark”. That their nature is a matter of opinion is clearly evident when explorer-naturalist Godfry Sykes decided that Fouquieria columnaris was as good a boojum as any and the name stuck.
An inflorescence on Fouquieria formosa flowering in December, Tehuacán Valley, Puebla-Oaxaca border area, México. Image: F. Muller.
“Ho, Ho, a Boojum – definitely a Boojum!”, he reportedly exclaimed on first seeing one through a telescope in the Sierra Bacha in Sonora in 1922 (Sykes 1982, Humphrey 1989, Felger et al. 2001).
Fouquieria species range in height at maturity from ~8’/2.5 m in the microendemic F. shrevei to ~82’/25 m in exceptional cases for wind-sheltered F. columnaris. Most are fully developed around the ~16-20’/5-6 m mark and have a very distinctive candelabrum type growth habit comprised of multiple, upright whip like stems emerging from a thick central stem of varying height. Many wild F. columnaris at exposed locations have twisted, arching or curlicued stems that make them look even more bizarre than typical forms.
A beautiful inflorescence on a spring flowering ocotillo, Fouquieria splendens, at Anza Borrego State Park, San Diego County, California. Image: R. Parsons.
Winter flowers on the Sonoran form of the palo Adán, Fouquieria diguetii, in a private collection, Scottsdale, Arizona.
All the Fouquieria species except F. shrevei, which have single axillary flowers, possess attractive to very showy inflorescences with white, yellowish, orange, pink, purple or bright red “firecracker” flower clusters. Blooming season varies across their respective ranges although they can broadly be divided into winter-early spring and summer flowering species. Red flowered ocotillos are especially attractive to hummingbirds but can also be visited by a variety of arthropod pollinators, especially carpenter bees (Xylocopa species; Scott 1989). The white-flowered species, especially F. columnaris, present a more complex picture with regards to their pollinators and recent studies suggest different pollinator guilds dominated by many bee species that vary from year to year in boojums across their range (Nabhan et al. 1999). Three ocotillo species are florally dichromatic. The shrubby F. diguetii from the southern half of Baja Californian Peninsula through to coastal regions of the mainland from Sonora south to Sinaloa and the Baja California Sur endemic, F. burragei, have two flower color forms, white and pink. The isolated Durango subspecies of F. splendens, ssp. campanulata, can have creamy-white to pinkish-violet corollas.
A winter inflorescence of a tree ocotillo, Fouquieria purpusii, in the Tehuacán Vallley, Puebla-Oaxaca border, México. Image: F. Muller.
Pachycaul ocotillos with fully succulent water storing stems include three highly desirable species for desert plant collectors: Fouquieria columnaris, F. fasciculata and F. purpusii. All three species have white flowers and were previously included in the genera Idria (F. columnaris) and Bronnia (F. fasciculata and F. purpusii). Phylogenetic analysis now indicates that all three are members of subgenus Bronnia (Redfern et al. 2008).
The species that are least represented in cultivation at this time are Fouquieria shrevei, a very rare narrow endemic gypsophile restricted to the Cuatro Ciénegas region of western Coahuila and northeastern Durango states, F. burragei, from the Gulf of California side of southern Baja California Sur, and F. leonilae, a fairly short-statured tree ocotillo from the Pacific slope foothills of north-central Guerrero, México.
Most of the local endemics are associated with specific edaphic conditions, especially limestone, gypsum, granite and basaltic formations, while the common, wider ranging species occur on a variety of well-drained soil types.
Trunk and stem details of a cultivated palo Adán, Fouquieria diguetii, in a private collection, Scottsdale, Arizona.
Branch detail on a young Fouquieria ochoterenae in the author’s Californa collection.
Members of this family are notable for conspicuous chloroplasts on their stems and branches that allow for photosynthesis in the absence of leaves. Several species also have waxy or resinous coatings on their stems to reduce transpiration. These features combine to present attractive patterns of orange to green stripes or bands on their stems. Foliage production in response to water can be dramatic, with fully expanded leaflets sometimes produced in as little as 48 hours following heavy rain. Likewise, ocotillos tend to shed these leaflets rapidly as humidity decreases and/or available soil moisture disappears. Unlike many dry forest deciduous trees and shrubs, members of this genus can leaf out multiple times annually in a rapid opportunistic response to favorable environmental conditions. Many of the tree type ocotillos, especially the southeastern Mexican forms, can retain leaves for prolonged periods in cultivation if they are watered frequently but should be dried out from time to time to maintain natural form and to reduce the risk of rot.
I am currently growing seven species of Fouquieria as pot plants in California and have grown two others in the past in Guatemala. Of the remaining species, while I have not grown it, I am familiar with F. burragei in nature on the Gulf of California side of the Cape in Baja California Sur. I have yet to handle a living F. shrevei but small examples do come to market in the U.S. from time to time and I have recently been offered first crack at some seedlings this summer (2020), so hope springs eternal. Most of the rarer species are now readily available in the form of two to three-year-old seed-grown plants selling online for USD 10.00-25.00 each.
International trade in three species is restricted under CITES, with Fouquieria fasciculata and F. purpusii currently listed under Appendix I (which also restricts cross border seed transfer) and F. columnaris listed on Appendix II. In vitro cultures of F. columnaris are specifically exempt from CITES permitting requirements (IUCN-CITES 2019).
Apart from the traditional destinations for illegally collected rare Mexican succulent plants (i.e. the U.S., eastern Europe and Japan), over the past decade or so a thriving market for rare Mexican and Central American stem succulents has also developed in the region. Social media has helped fuel demand for wild collected plants of desirable species in México, Guatemala and El Salvador (pers. obs.). The two southeastern Mexican tree ocotillos mentioned in the previous paragraph are now subject to extraction pressure from local rare plant collectors as well as Gringos.
A nicely shaped young tree ocotillo, Fouquiería purpusii, showing leaf change in nature, Tehuacán Valley, Puebla-Oaxaca border, México. Image: F. Muller.
Salvaged ocotillos (Fouquieria splendens), mostly fully mature specimens removed during residential development or road construction, are widely available in Arizona, California and Texas. They usually take about a year to re-establish from bare-root stock. Properly handled plants have a surprisingly high survival rate despite severe root pruning and rough handling, with some sources suggesting 90% success with salvaged material in Arizona (USDA Technical Note on Plant Materials 2009). Legally collected wild ocotillos at points of sale will carry state native plant and/or USDA tags. These tags can be removed once material is planted, but receipts or tags should be kept on file for a few years as proof of legality where needed. Nursery-grown stock does not require tags for transport nor possession. Observations made recently at a few nurseries in Arizona and California strongly suggests that old, wild collected material of several north and central Mexican Fouquieria species continues to leak over the border and into the U.S. horticultural trade.
A young ocotillo macho (Fouquieria macdougalli) flowering in a California greenhouse in mid-July. Author’s plant and image.
Fouquieria seed is generally easy to germinate and success rates are frequently high with fresh, properly stored material. Unless large numbers of plants are required by the grower, purchase of established seedlings from reputable online nurseries is often more time and cost effective than seed sow.
A cultivated seed-grown boojum, Fouquieria columnaris, in a private collection in Scottsdale, Arizona, shown left in winter at 11 years of age, and right at 16 years old. Over this time period, the sapling has doubled in height and increased by several multiples of total biomass. Forced plants can grow faster than this in youth. At the size shown right, boojums begin to elongate fairly rapidly…it’s summoning the patience required to get them from seed to this stage that’s the challenge!
Ocotillos have been hybridized in attempts to enhance caudex form (e.g. Fouquieria fasciculata x purpusii) as well as to combine red flowered candelabraform types with other pachycaul species (Houston and Stead 2009). An attractive 2013 ISI release is F. ‘Pink Instead’ (F. purpusii x F. macdougalii) that has – no surprise – pink flowers.
A very handsome mature example of the tree ocotillo, Fouquieria purpusii, flowering in nature in the Tehuacán Valley, Puebla-Oaxaca border, México. Image: F. Muller.
Although three-year-old potted Fouquieria columnaris in 4”/10 cm pots can be purchased for as little as USD 10.00 each from some online nurseries in the U.S., giant, specimen sized domestically propagated boojums can fetch well north of USD 20,000.00 (plus transport and installation) at nurseries in Arizona. Four to 6’/1.20-1.85 m nursery-grown F. purpusii and F. diguetii are currently (2020) offered for sale between USD 1,300.00 and 2,500.00. Over the past several years, commercial availability in the U.S. of seedlings and young examples of all the horticulturally desirable species except F. shrevei has increased dramatically, with prices for one gallon/3.80 lt pot sized F. purpusii and F. fasciculata having been cut in half since 2010. While large candelabraform ocotillos are generally not available outside of the U.S. and México, smaller specimen plants of F. columnaris, F. fasciculata and F. purpusii are available at high prices from commercial sources in the EU and parts of east Asia.
Specialty nurseries in southern Arizona have produced specimen sized Fouquieria columnaris from in ground plantings since the late 1970s, so fair numbers of large examples of these remarkable trees have made it to regional landscapes over the past 40+ years. Their first decade after seed sow seems to be spent developing girth and branches rather than height. With supplemental irrigation and fertilization, warm climate boojums can add as much as 10-12”/25-30 cm in height annually once they reach about 24”/60 cm tall. They are definitely “trophy” trees when big; quite sizeable specimens can be seen in gardens in the upscale neighborhoods in and around Scottsdale, Arizona. They are also standard fare for all of the Arizona and southern Californian botanical gardens, and many well grown large specimens may be seen as visual anchors in these collections.
Although boojums in the garden are admittedly not to everyone’s taste, the red flowered native ocotillo species is extremely popular with landscapers and gardeners across the U.S. southwest, especially in Arizona and California desert communities.
Two salvaged ocotillos, Fouquieria splendens, flowering in a a street side planting in a north Scottsdale, Arizona residential development. Large numbers of wild ocotillos are spared every year in these “re-homing” projects throughout the U.S. southwest.
Because larger boojums and ocotillos are very slow growing, plants intended for landscape installations should best be purchased as close to final desired size as possible. Most succulent collectors outside of their range states grow them more as token curiosities or conversation pieces rather than with any real hope of the plants attaining mature sizes in their care. That said, seedling origin plants grown in both large containers and in the ground under optimal conditions can achieve respectable sizes over the course of 12-15 years and fully branched, 6-8’/1.85-2.45 m plants may be successfully produced within this time frame. These plants are fairly shallow rooted and very sensitive to rot, so substrates should be comprised of high percentages (>50%) of mineral content and watering should generally be timed to the plant’s natural growth cycle.
A pair of young, seed-grown Fouquieria purpusii flanking a small F. fasciculata greenhoused in the author’s California collection. Tallest plant shown ~40”/100 cm. These shrubs can be surprisingly fast growing when conditions are optimal.
All species require a minimum of several hours (preferably more) of full sun daily to thrive. Under greenhouse conditions, potted plants should be provided with a well-lit location and watered with care. I prefer terra cotta pots for my plants a variety of reasons, but nursery grown Fouquieria species are normally offered for sale in plastic pots and appear to thrive when grown in them as well. In my experience, they respond positively to biannual fertilization with any timed-release complete fertilizer. I add extra dolomite and encapsulated gypsum to the base mixes of species occurring on limestone and gypsum soils in nature.
Under the high summer rainfall conditions that prevail in the Guatemalan highlands, I drenched the Fouquieria species that I grew there with Banrot (Etridiazole + Thiophanate-methyl) at recommended rates every 45-60 days to prevent rots and losses.
The Anza Borrego Desert in spring bloom following a wet winter. Flowering ocotillos, Fouquieria splendens, are a conspicuous feature of the landscape here. Image: F. Parsons.
A very old, multi-stemmed boojum, Fouquieria columnaris, Desert Botanical Garden, Phoenix, Arizona.
The species that occur in the southwestern U.S., Sonora, Baja California and Coahuila are all very cold tolerant and can survive temperatures well below freezing when in the ground. The southeastern Mexican endemics are significantly less hardy and probably should be kept where temperatures don’t drop much below 40 degrees F/4.5 C., even for brief periods. As with all stem succulents, plants in airy spots with dry substrates and plenty of exposure to sunshine handle extreme low temperatures far better than wet, partially shaded plants.
PLEASE NOTE: Besides warranting sturdy gloves when handling larger examples, be aware that the very spiny, stiff, often sharp-tipped stems of the candelabraform ocotillos represent a very real hazard to eyes. Use common sense and glasses when working in close with larger shrubs.
For those interested in this family, there is a wealth of good information on boojums and ocotillos online. As always, select sources with care since there is a lot of nonsense written about them as well. I also recommend James Henrickson’s exhaustive 1972 revision of the Fouquieriaceae for those willing to peer closely into the taxonomy and ecology of these remarkable plants. Almost 50 years after its publication it remains the authoritative work on boojums and ocotillos.
“…They hunted till darkness came on, but they found
Not a button, or feather or mark,
By which they could tell that they stood on the ground
Where the Baker had met with the Snark.
In the midst of the word he was trying to say,
In the midst of his laughter and glee,
He had softly and suddenly vanished away,
For the Snark was a Boojum, you see.”
Winter-flowering boojums together with senita (Lophocereus schottii) and saguaro cacti (Carnegiea gigantea) in a planting at the Arizona-Sonora Desert Museum outside Tucson, Arizona.
Acknowledgements
Fred Muller and Ron Parsons provided the excellent images of flowering wild ocotillos shown above in the Tehuacán Valley in Puebla-Oaxaca, México and in Anza Borrego State Park, San Diego County, California. All other images are the author’s.
All content ©Exotica Esoterica LLC® 2020, ©Fred Muller 2020, ©Ron Parsons 2020, and ©Jay Vannini 2020
