The Gymnosperm Database
in habitat (Institute of Plant Ecology 1997) [Dieter von Willert].
A cultivated specimen (Carr 2002) [Gerald D. Carr].
A cultivated specimen showing pollen cones (Botanischer Garten und Botanisches Museum Berlin-Dahlem 1997).
A wild specimen with three leaves (Alex Harvey e-mail 2003.04.12).
See also the
Welwitchia Images of Dierk Wanke
Tree tumbo (Anonymous [no date]), welwitschia, tumboa, n'tumbo [Angolan], tweeblaarkanniedood [Afrikaans] !kharos [Nama/Damara], nyanka [Damara], khurub [Nama], onyanga [Herero] (Notten 2003).
The sole species in order
Skottsburg ex Reveal 1993, family Welwitschiaceae Caruel 1879, genus
Hooker f. 1862. Synonyms for these include Tumboaceae Wettst. 1903,
(Hooker f.) Carrière 1867,
Hooker f. 1861, and
Hooker f. 1862. Some authorities even put it in a class by itself,
B. Boivin 1956.
The family seems to have arisen via a whole-genome-duplication (polyploidy) event that separated it from the clade now represented by
(Li et al. 2015). This plant is nearly unknown in the fossil record. The most noteworthy finds are from the lower Cretaceous (Aptian, ca. 112-114 ma) Crato Formation of northeast Brazil. These fossils include young stems with attached cotyledons, isolated leaves, and axils bearing male cones (Dilcher et al. 2005), and by inference, providing a minimum date for divergence of
Leuenberger (2001) has described the Angolan and Namibian as two subspecies, differentiated on the basis of male cone characters. The subspecies are
Leuenberger. He has offered the following key (Leuenberger 2001):
Male cones smooth, purplish brown (rarely green when shaded), without evident wax cover; longer peduncles usually c. 5-11 cm long, secondary branches to 2 cm long; longest male cones 30-45 mm long; bract pairs overlapping c. 2 mm; bract scales more than 3/4 connate, margin of bracts smooth; Angola
Male cones sculptured, glaucous green to salmon, with evident wax cover; longer peduncles c. 7-15 cm long, secondary branches to 7 cm long; longest male cones 20-30 cm long; bract pairs overlapping c. 1 mm; bract scales ⅓ -⅔ connate, margin of bracts slightly erose; Namibia
Dioecious perennial plant with short stem and taproot. Beyond that, the plant is often described as 'bizarre', 'weird', or (more explicitly) 'unlike any known plant on earth'. Its short, woody, unbranched stem is surmounted by 2 (rarely 3: see photo) strap-shaped leaves that grow from a basal meristem throughout the life of the plant, becoming twisted and frayed with the passing centuries. The leaves contain numerous subparallel veins that may anastomose or terminate blindly in the mesophyll (this character is unique in
among the gymnosperms). Stomata occur on both leaf surfaces. The woody stem widens with age to become a concave disc up to a meter across, from which grow small ramified branch systems that serve only to bear pollen and seed cones (Gifford and Foster 1988). The branched reproductive shoots arise near the leaf bases. Pollen cones red, resembling those of
, appearing in groups of 2-3 terminally on each branch. Ovulate cones also arising from branched reproductive shoots, each red cone consisting of a single nucellus enclosed in an integument and another layer derived from two confluent primordia ('perianth') with 2 'bracts'. Normally, only one seed develops within each cone; it is dispersed by wind with 'perianth' as a wing. Seeds germinate in wet years, the 2 cotyledons photosynthesizing for 1.5 years (Anonymous [no date], Gifford and Foster 1988).
Distribution and Ecology
A disjunct distribution in SW Africa. The type locality is in the vicinity of Cabo Negro on the coast of Angola (latitude 15-16° S), while more widely dispersed populations are found from the coast to ca. 200 km inland in Namibia (latitude 20-24° S). The area is extremely arid, receiving no rainfall in some years and averaging fewer than 100 mm per year. Most specimens are found within 80 km of the coast in a fog belt, suggesting that the fog is an important moisture source (Rodin 1953).
Distribution, based on herbarium records downloaded from the
. Click on individual records (tree icons) for links to the source data.
Leaves typically grow at a rate of 8-15 cm/yr on mature plants, some of which have been found with leaves measuring 1.8 m wide and 6.2 m long, suggesting potential ages of 500-1000 years. Ages of 1500-2000 years have been claimed without supporting data (Gifford and Foster 1988).
I do not know of any investigations, but suspect it is impossible in view of the plant's peculiar morphology.
Discovered by Friederich Welwitsch (1806-1872) in 1860 (Rodin 1953), and described by him the following year (Welwitsch 1861).
Some remarkably detailed ecophysiological studies have been performed, cited below and available online at (Institute of Plant Ecology 1997). The findings are rather complex but seem to suggest that the plant requires periods of high humidity (i.e. fogs) if it is to sustain a positive carbon balance. It may survive the absence of such conditions for as much as 150 days -- possibly much longer.
is also of considerable ecophysiological interest because it is a so-called CAM or C4 plant, meaning that it uses the crassulacean acid metabolic pathway in photosynthesis (von Willert et al. 2005). This metabolic pathway is common in cacti and other desert succulents because it enables carbon dioxide absorption during the night, and then photosynthesis with closed stomata during the day; this increases plant water use efficiency. Although CAM is common among angiosperms, among the gymnosperms it has only been recorded in
and in the cycad
(although it will probably be found in other cycads, too).
"Difficult to cultivate requiring desert conditons and room to accomodate its long taproot. Propagated by seeds." Temperature: 10-12°C at night, 21-23°C during the day. Light: Bright light or full sun. Watering: Drench thoroughly, allow to become dry between waterings (Anonymous [no date]).
Anonymous. [no date]. Welwitschia mirabilis. Web page maintained by University of Connecticut Department of Ecology and Evolutionary Biology at
, accessed 2007.12.11. This page contains useful information and several links to other
Botanischer Garten und Botanisches Museum Berlin-Dahlem, Freie Universität Berlin. 1997.02.05. Welwitschia-Annex. http://www.bgbm.fu-berlin.de/bgbm/pr/garden/bereiche/areas/welwitsh.htm, accessed 1999.02.24, now
but a very similar page is at
Carr, Gerald D. 2002. Non-Flowering Plant Families.
, accessed 2007.12.11.
Dilcher, David L., Mary E. Bernardes-de-Oliveira, Denise Pons, and Terry A. Lott. 2005. Welwitschiaceae from the lower Cretaceous of northeastern Brazil.
American Journal of Botany
Gifford, Ernest M. and Adriance S. Foster. 1988. Comparative morphology of vascular plants, 3rd ed. New York: W.H. Freeman (Chapter 18).
Institute of Plant Ecology. 1997.02.17. Welwitschia mirabilis. http://www.uni-muenster.de/Biologie/pflanzenoekologie/science/willert/vw_welwmira.htm, accessed 1999.02.24, now
Leuenberger, B.E. 2001.
Li, Zheng, Anthony E. Baniaga, Emily B. Sessa, Moira Scascitelli, Sean W. Graham, Loren H. Rieseberg, and Michael S. Barker. 2015. Early genome duplications in conifers and other seed plants.
Notten, Alice. 2003. Welwitschia mirabilis Hook.f.
, accessed 2014.12.28.
Rodin, R.J. 1953. Distribution of
Welwitschia mirabilis. American Journal of Botany
von Willert, D.J., N. Armbrüster, T. Drees, and M. Zaborowski. 2005. Welwitschia mirabilis: CAM or not CAM — what is the answer?
Functional Plant Biology
Welwitsch, F.M.J. 1861. On the botany of Benguela, Mossamedes, etc., in western Africa.
Journal of the Linnaean Society (Botany)
Bornman, C. H. 1972.
: paradox of the Namib desert.
Brinckmann, E. and D. J. von Willert. 1987. Injury and recovery of
Welwitschia mirabilis. Dinteria
Bustard, L. 1990. The ugliest plant of the world: the story of
Carlquist, S. and D. A. Gowans. 1995. Secondary growth and wood histology of
Welwitschia. Botanical journal of the Linnean Society
Chamberlain, Charles. J. 1906.
Welwitschia. Botanical Gazette
Chamberlain, Charles. J. 1921.
Welwitschia mirabilis. Botanical Gazette
Cooper-Drive, Gillian A. 1994.
- a dream come true.
Crane, P. and C. D. Hult. 1988.
the wonderful. Life as a survivor in the desert of southwestern Africa.
Field Museum of Natural History Bulletin
Craven, P. and C. Marais. 1986.
Namib Flora: Swakopmund to the Giant Welwitschia via Goanikontes
. Windhoek, Namibia: Gamsberg Macmillan.
Curtis, B. and C. Mannheimer. 2005.
Tree Atlas of Namibia
. Windhoek: National Botanical Research Institute.
Dilcher, D. L., M. E. Bernardes-De-Oliveira, D. Pons, and T. A. Lott. 2005. Welwitschiaceae from the Lower Cretaceous of northeastern Brazil.
American Journal of Botany
Henschel, Joh R. and Mary K. Seely. 2004. Long-term growth patterns of
, a long-lived plant of the Namib Desert (including a bibliography).
Herppich, W.B., B.M.-T. Flach, D.J. von Willert, and M. Herppich. 1996. Field investigations of photosynthetic activity, gas exchange and water potential at different leaf ages in
during a severe drought.
Hooker, J. D. 1863. On
, a new genus of Gnetaceae.
Transactions of the Linnean Society of London
Jacobson, K. M., P. J. Jacobson and O. K. J. Miller. 1993. The mycorrhizal status of
Welwitschia mirabilis. Mycorrhiza
Jacobson K. M., and E. Lester. 2003. A first assessment of genetic variation in
Journal of Heredity
Khoshoo, T.N. and Ahuja, M.R. 1962. The karyotype in
Khoshoo, T.N. and Ahuja, M.R. 1963. The chromosomes and relationship of
Kers, L. E. 1967. The distribution of
Svensk Botanisk Tidskrift
Marsh, B. A. 1990. The microenvironment associated with
in the Namib desert. Pp. 149-153
M. K. Seely, ed.:
Namib Ecology, 25 years of Namib Research
. Pretoria: Transvaal Museum.
Masters, Maxwell T. 1898. The source of
Welwitschia. Botanical Gazette
Mshigeni, Keto, and Grant Wardell-Johnson. 1996.
, an enigma from the Namib desert.
Discovery and Innovation
Mundry, M. and T. Stutzel. 2004. Morphogenesis of the reproductive shoots of
(Gnetales), and its evolutionary implications.
Organisms Diversity & Evolution
Rydin C., B. Mohr, and E. M. Friis 2003. Cratonia cotyledon gen. et sp. nov.: a unique Cretaceous seedling related to Welwitschia.
Proceedings of the Royal Society of London B, Biology Letters (Supplement)
. The authors hope that one day this will develop into a comprehensive global flora. For now (2007.12.11), it has an excellent description of Welwitschiaceae,
Van Jaarsveld, Ernst. 1990. The cultivation and care of
: the extraordinary caudiciform from the Namib Desert.
Van Jaarsveld, Ernst. 1992.
in cultivation at Kirstenbosch.
Veld & Flora
Van Jaarsveld, Ernst. 2000.
Welwitschia mirabilis. Veld & Flora
Van Jaarsveld, Ernst and Uschi Pond. 2013.
Uncrowned monarch of the Namib: Welwitschia mirabilis
. Cape Town: Penrock Publications.
Vascular Plant Image Gallery, web page
, accessed 1999.02.21. This page has about 20 photographs of the plant and its structures.
Von Willert, Dieter J. 1985.
- New aspects in the biology of an old plant.
Advances in Botanical Research
Von Willert, Dieter J. 1994.
Hook. fil.- das Überlebenswunder der Namibwüste [the survival miracle of the Namib desert].
Von Willert, D.J. and U. Wagner-Douglas. 1994. Water relations, CO2 exchange, water-use efficiency and growth of
Hook. fil. in three contrasting habitats of the Namib desert.
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