| | Family guide for fruits and seeds |
Common name: Clethra Family.
Number of genera 1. Number of species 64.
Angiosperm. Magnoliopsida.
Disseminule a dehisced fruit, or a seed.
Fruits
Pistil(s) compound; 1; 1-pistillate; with carpels united. Fruit pericarpium; simple; capsule; septifragal capsule (Spjut), or loculicidal capsule (of authors, not Spjut); capsule not inflated; capsule without operculum; with persistent central column; valves not diverging at top of central column; not within accessory organ(s); 10 to less than 25-seeded; many; 3-carpellate; with carpels united; without sterile carpels; not sulcate; apex not beaked; dehiscent. Dehiscent unit seed(s). Dehiscent regularly; and shedding seeds; without replum. Epicarp durable; without armature; not smooth; tuberculate, or verrucose; without wing(s); without apical respiratory hole. Endocarp present; not separating from exocarp; thin; not splitting into 1-seeded pyrenes; smooth; without wing; without operculum; without secretory cavities; without grooves; without longitudinal ridges. Funiculus short; short without seed bearing hooks (retinacula); not persisting in fruit after seed shed.
Seeds
Aril absent. Seed minute; not bowl shaped; not nutlike; without winglike beak; without caudate appendage(s); at maturity with food reserves; with endosperm; without canavanine. Sarcotesta absent. Testa present; without fleshy or leathery layer over hard layer; surface unsmooth; surface with merged raised features; surface reticulate; 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; with wing(s), or without wings (seldom); 2-winged; with wings on both sides; without collar; without operculum; colored; monochrome; thin (single cell layer); not becoming mucilaginous when wetted; surrounding food reserve. Endosperm development cellular; moderate (copious according to Mabberley); fleshy; smooth; with oils; without fatty acid containing cyclopropene; without apical lobes; without chlorophyll; without isodiametric faceted surface; without odor.
Embryo differentiated from food reserve; well developed; 1 per seed; partially filling testa (with food reserve); 0.9 times the length of food reserve; at one end of seed not extending into a depression or cup; axile and centric; linear; straight; parallel to seed length; with cotyledons abruptly connected to hypocotyl-radicle; without coleorhiza; without simmondsin; without stomata; not green; with 2 or more cotyledons. Cotyledons 2; well developed; 0.25 times length of embryo; somewhat to significantly wider than hypocotyl-radicle; smooth; with apices entire; with margins separate; basally cordate (more or less); equal in size; not punctate dotted. Hypocotyl-radicle moderately developed; coiled; not thickened.
Distribution
Cosmopolitan. New World, Old World. North America, Middle America, South America, Asia Major, southeastern Asia (to Japan and China).
Notes
Spjut recorded septigragal capsule because of "incompletely opening along the dorsal or ventral sutures by break in partitions near central axis, leaving a persistent columella. often valves have separated". Fernald (1950) "placentae remaining attached to the columella".
Weed information
No USA noxious weeds.
Listed seeds
ISTA listed seeds.
ISTA listed seeds: -- Clethra acuminata Michx. -- Clethra alnifolia L. -- Clethra barbinervis Siebold & Zucc. -- Clethra fargesii Franch. -- Clethra tomentosa Lam. = Clethra alnifolia L. -- Symbols: aagricultural and vegetable seeds (Table 2A Part 1); ttree and shrub species (Table 2A Part 2); fflower, spice, herb, and medicinal seeds (Table 2A Part 3); wweed seeds. -- Last updated September 2008.
Accepted genera
Clethra L.
References specific to this family
Cronquist page 469. Fernald, M.L. 1950. Gray's Manual of Botany, 8th Ed., 1,632 p. American Book Co., New York.
General references
Cronquist, A. 1981. An integrated system of classification of flowering plants, 1,262 p. Columbia University Press, New York, Engler, A. and K. Prantl. 1924 and onward. Die Natürlichen Pflanzenfamilimien. W. Engelman, Leipzig, Gaertner, J. 1788–1805. De fructibus et seminibus plantarum. The Author, Stuttgart, Goldberg, A. 1986 (dicots) and 1989 (monocots). Classification, evolution, and phylogeny of the familes of Dicotyledons. Smithsonian Contr. Bot. 58 for dicots (314 pp.) and 71 for monocots (74 pp.). [Goldberg's illustrations are reproduced from older publications and these should be consulted], 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, Spjut, R.W. 1994. A systematic treatment of fruit types. Mem. New York Bot. Gard. 70:1–182.
Illustrations
No fruit and poor seed illustrations. Disseminule illustration(s): seed, or embryo. Seed illustration(s): Karen, Engler & Prantl. Embryo illustration(s): Karen, Engler & Prantl. Karen's plate number and taxon (taxa): 140: Clethra arborea Aiton (A-B).
• Fruit. 1 of 5. Clethra arborea Aiton: fruits . • Fruit. 2 of 5. Clethra arborea Aiton: fruit with exocarp removed. • Seed. 3 of 5. Clethra arborea Aiton: seed. • Embryo. 4 of 5. Clethra arborea Aiton: embryo. • Embryo. 5 of 5. Purdiaea cubensis (A. Rich) Planch.: 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’.
