Neotropical Fouquieriaceae

Jon L.R. Every

Royal Botanic Gardens, Kew, UK. 

Description

Xerophytic shrubs, small trees or cactus-like columnar-stemmed succulents, long and short shoots present, long shoots armed with petiolar spines 2-45mm long, short shoots axillary to spines producing secondary clustered leaves that do not form spines. Leaves alternate, simple, clustered or single, succulent, exstipulate, almost sessile or petiolate, margins entire (sometimes revolute), venation pinnate, both surfaces glabrous or slightly pubescent below. Inflorescences determinate, terminal or axillary, corymbs, panicles, racemes or spikes; rachis occasionally coloured (maroon, pink, purple, red or seldom green). Flowers actinomorphic, bisexual, showy, with two prophylls, sessile to pedicellate; calyx with 5 sepals, these free, imbricate, unequal (two outer lobes smaller than the inner three), persistent in fruit; corolla 5 lobed, tubular, lobes imbricate; stamens 10-16(-23), unevenly exserted, filaments free or slightly fused, slightly adnate to corolla base, occasionally with a puberulent, red-coloured basal ligulate spur, anthers dorsifixed, longitudinally dehiscent; gynoecium syncarpous, ovary superior, carpels 3, locule 1, style 1, three-branched or entire, exserted or included in the corolla, ovules 6-16(20). Fruits loculicidal, dehiscent capsules with three, thick, coriaceous valves. Seeds 3-13(-18), winged (formed by a dense fringe of unicellular trichomes), flattened, 8-20mm in total length.

Notes on delimitation

  • Currently placed in the Ericales as sister to Polemoniaceae (Stevens 2008).
  • Has been previously placed in the Violales sensu Cronquist.
  • Included in its own order, the Fouquieriales sensu Takhatajan ex Reveal.

Distribution in the Neotropics

  • Found growing outside the floristic region from southern U.S.A to the north Mexican desert in areas receiving 50-350 mm rainfall.
  • Species in southern Mexico grow in deciduous tropical forest and arid tropical scrub averaging mostly 400-700mm rainfall.

Distinguishing characters (always present)

  • Long, vicious spines on the longer stems.
  • Primary leaves on the long shoots have long petioles.

Other important characters

  • Flower colour varies amongst the taxa as do the number of stamens, the degree of corolla limb reflexion and their pattern of arrangement in the inflorescences.
  • Intermediate between typical xeromorphic types (neither stem succulents nor shrubs).
  • Woody or succulent habit and also both woody and succulent parts on the same plant.
  • Deciduous during drought periods between the rains (leaves can re appear in as little as 48hrs after rainfall).
  • Short shoots axillary to spines producing secondary clustered (almost sessile) leaves which do not form spines.
  • Brightly coloured flowers: yellow (subgen. Idria (Kellogg) Henrickson) or red (subgen. Fouquieria Kunth).
  • Style three-branched (subgen. Fouquieria and subgen. Bronnia Kunth) or entire (subgen. Idria).

Number of genera

1: Fouquieria Kunth with eleven species.

  • Molecular analysis has complemented the work done by Henrickson (1972) regarding the intra-familial relationships, recognizing the three subgenera as monophyletic groups:
    -Subgenus Bronnia and Idria comprise the succulent species
    -Subgenus Fouquieria contains eight woody species
  • Nash (1903) treated Fouquieria and Idria as separate genera, separating them by degrees of style fusion, stamen exerstion/inclusion, habit and corolla colour.

Status

  • The majority of the Fouquieriaceae species are endemic to mainland Mexico.

General notes

  • Also known as the Ocotillo and Candlewood family.
  • Trade in many species is restricted by CITES due to the small populations.
  • Fouquieria owes its name to P.E. Fouquier, a Parisian professor of medicine.
  • Both insect- (entomophilic) and bird- (ornithophilic) pollinated species are found, depending on the shape, size and colour of flowers.
  • Trichomes at the base of the stamens are thought to achieve two things: firstly they reduce the evaporation of nectar from the base of the flower, and secondly they draw the nectar (by means of capillary & action) up and away from the sensitive ovary, protecting it from the beaks of hummingbirds.
  • Waxy exudates from F. shrevei I.M.Johnst. are said to produce an agreeable aroma when burnt.
  • F. splendens Engelm. has a dynamic range of uses from providing a quick snack in the form of the nectariferous flowers, to use as living fences and as a boot wax.
  • F. columnaris (Kellogg) Curran is used to provide fence posts.
  • The bark of F. macdougalii Nash has been used as a soap.

Important literature

Henrickson J. 1972 A taxonomic revision of the Fouquieriaceae. Aliso 7. (4): 439-537

Heywood, V. H., Brummitt, R. K., Culham, A. and Seberg, O. (eds.). Flowering plant families of the world, p. 150. Royal Botanic Gardens, Kew.

Kubitzki, K. 2004a. Fouquieriaceae. Pp. 1-11. In Kubitzki, K. (ed.). Families and genera of vascular plants. Volume 6. Flowering plants. Dicotyledons. Springer-Verlag, Berlin.

Maas, P. J. M. & Westra, L. Y. Th. 2005. Neotropical Plant Families. 3rd ed. P. 247. A.R.G. Gantner Verlag K.G., Ruggell.

Nash, G. V. 1903. A Revision of the Family Fouquieriaceae. Bulletin of the Torrey Botanical Club 30(8): 449-459.

Schultheis, L. M. and Baldwin, B. G. 1999. Molecular Phylogenetics of Fouquieriaceae: Evidence from Nuclear rDNA ITS Studies. American Journal of Botany 86(4): 578-589.

Smith, N. 2004. Fouquieriaceae. Pp. 161-2. In: Smith, N., Mori, S. A., Henderson, A., Stevenson, D. W. and Heald, S. V. (eds.). Flowering Plants of the Neotropics. The New York Botanical Garden, Princeton University Press, Princeton.

Stevens, P. F. (2008). Angiosperm Phylogeny Website. Version 9 onwards. http://www.mobot.org/MOBOT/research/APweb/.

Watson, L. and Dallwitz, M.J. (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 14th December 2000.

How to cite

Every, J.L.R. (2009). Neotropical Fouquieriaceae. In: Milliken, W., Klitgård, B. & Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://www.kew.org/science/tropamerica/neotropikey/families/Fouquieriaceae.htm.