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Synonyms: Tumboaceae Wettst.
Common name: Welwitschia Family.
Number of genera 1. Number of species 1 (Welwitschia mirabilis Hook. f.).
Gymnosperm.
Disseminule a cone, or a seed.
Cones
Cone dry; when dry compound (Spjut 2 families: Pinaceae, Welwitschiaceae); oblong; symmetrical. Fruiting scales present; dry; persisting.
Seeds
Aril absent. Seed larger than minute; not bowl shaped; not nutlike; without winglike beak; without caudate appendage(s); at maturity but Airy Shaw has both endosperm and perisperm; without canavanine. Sarcotesta absent. Testa present; with markedly different marginal tissue; without fleshy or leathery layer over hard layer; tight; surface unsmooth; without crease or line separating cotyledons from hypocotyl-radicle; without notch along margin where cotyledons from hypocotyl-radicle tip approach each other; without glands; without bristles; glabrous; with wing(s); 1-winged ("perianth" wing); with wing encompassing seed; without collar; without operculum; colored; monochrome; membranous, or coriaceous, or fleshy; not becoming mucilaginous when wetted; surrounding food reserve.
Embryo differentiated from food reserve; well developed; 1 per seed; partially filling testa (with food reserve); chamber central to wings; 0.7 times the length of food reserve; at one end of seed not extending into a depression or cup; apical, or axile and centric; linear; straight (more or less); parallel to seed length; embedded in endosperm; with cotyledons gradually connected to hypocotyl-radicle; without coleorhiza; without simmondsin; without stomata; not green; with 2 or more cotyledons. Cotyledons equal in size; not punctate dotted.
Distribution
Old World. Southwestern & Angola Africa.
Notes
Kubitzi in Kramer & Green: "Seed enclosed in the membranous winged 'perianth". Seed dispered with 'perianth' as a wing. Two median bracts form the seed wing. Seed is enclosed in membranous winged "perianth". Airy Shaw: Compound cones of perianth-leaves, and seed with endosperm and perisperm.
Weed information
No USA noxious weeds.
Listed seeds
No ASOA or ISTA listed seeds.
Accepted genera
Welwitschia Hook. f., nom. cons.
References specific to this family
Cronquist page 0 (not present).
General references
Airy Shaw, H.K. 1973. A dictionary of the flowering plants and ferns, 1,131 pp. University Press, Cambridge, Engler, A. and K. Prantl. 1924 and onward. Die Natürlichen Pflanzenfamilimien. W. Engelman, Leipzig, Gunn, C.R., J.H. Wiersema, C.A. Ritchie, and J.H. Kirkbride, Jr. 1992 and amendments. Families and genera of Spermatophytes recognized by the Agricultural Research Service. Techn. Bull. U.S.D.A. 1796:1–500, Kubitzki, K. 1990. Gnetatae with the single living order Gnetales. In: Kubitzki, K., ed., The families and genera of vascular plants, vol. 1, pp. 378–391. Springer-Verlag, Berlin, LeMaout, E. and J. Decaisne. 1876. A general system of botany, 1,065 p. Longmans, Green, and Co., London, Mabberley, D.J. 1987. The plant-book, 706 p. Cambridge University Press, Cambridge, Spjut, R.W. 1994. A systematic treatment of fruit types. Mem. New York Bot. Gard. 70:1–182.
Illustrations
Excellent compound cone & seed illustrations. Disseminule illustration(s): "cone", or seed, or embryo. Illustrated "cone": compound cone. "Cone" illustration(s): Kubitzki (in Kramer & Green), LeMaout & Decaisne, Engler & Prantl. Seed illustration(s): Kubitzki in Kramer & Green, LeMaout & Decaisne, Engler & Prantl, Karen. Embryo illustration(s): Engler & Prantl, Karen. Karen's plate number and taxon (taxa): 414: Welwitschia mirabilis Hook. f.(A-B).
• Cone. 1 of 4. Welwitschia mirabilis Hook. f.: cone. • Scale. 2 of 4. Welwitschia mirabilis Hook. f.: scale. • Seed. 3 of 4. Welwitschia mirabilis Hook. f.: seeds. • Embryo. 4 of 4. Welwitschia mirabilis Hook. f.: embryo.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘J.H. Kirkbride, Jr., C.R. Gunn, and M.J. Dallwitz. 2000 onwards. Family guide for fruits and seeds: descriptions, illustrations, identification, and information retrieval. Version: 12th April 2021. delta-intkey.com’.
