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Synonyms: Rhopalocarpaceae Hemsl. ex Takht.
Common name: Rhopalocarpus Family.
Number of genera 2. Number of species 17.
Angiosperm. Magnoliopsida.
Disseminule an intact or entire fruit.
Fruits
Pistil(s) compound (Rhopalocarpus), or simple (Dialyceras); 1, or 2–5; 1–4-pistillate; with carpels separate to base, or carpels united. Fruit pericarpium; simple (Rhopalocarpus), or multiple (Dialyceras); carcerulus (Rhopalocarpus); achenetum (Dialyceras); without persistent central column; without style or stylar remnants; not within accessory organ(s); 1-seeded, or more than 1 but less than 10-seeded; 1–4-seeded; from 1–5 cm long; 1.5–2 cm long; 1–4-carpellate; with carpels united (Rhopalocarpus), or separate (Dialyceras); with carpels remaining united at maturity (Rhopalocarpus); with carpels not radiating at maturity (Rhopalocarpus), or radiating at maturity (Dialyceras); with carpels remaining connected at style; without sterile carpels, or with sterile carpels; without fleshy lateral appendage; not sulcate; in transection terete; apex not beaked (Rhopalocarpus), or beaked (Dialyceras); apex moderately beaked; wall fleshy to hard; indehiscent. Epicarp brown (all shades); dull; durable; hard; glabrous (without hairs); without armature; not smooth (Rhopalocarpus), or smooth (Dialyceras); muricate; without wing(s); without apical respiratory hole. Mesocarp present; hard; composed of 1 unified layer; without lactiform cavity system; and endocarp sharply differentiated. Endocarp present; not separating from exocarp; firm; not splitting into 1-seeded pyrenes; without wing; without operculum; without secretory cavities; without mechanism for seedling escape; without grooves; without longitudinal ridges.
Seeds
Aril absent. Seed larger than minute; 10 to less than 25 mm long; 16 mm long; ovate; in transection terete; 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 markedly different marginal tissue; without pellicle layer; without fleshy or leathery layer over hard layer; tight; dull; surface smooth; 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; without wings; without collar; without operculum; colored; monochrome; brown (all shades); hard; not becoming mucilaginous when wetted; surrounding embryo. Hilum larger than punctate; marginal; elliptic. Raphe conspicuous. Endosperm moderate; smooth, or ruminate; without fatty acid containing cyclopropene; without chlorophyll; without odor.
Embryo differentiated from food reserve; well developed; 1 per seed; partially filling testa (with food reserve), or nearly filling testa (trace or scanty food reserve); at one end of seed not extending into a depression or cup; axile and centric; foliate; with investing cotyledons; straight; parallel to seed length; embedded in endosperm; with cotyledons abruptly connected to hypocotyl-radicle; without coleorhiza; without simmondsin; with cotyledons containing oils; without stomata; not green; with 2 or more cotyledons. Cotyledons 2; well developed; 0.5–0.8 times length of embryo; somewhat to significantly wider than hypocotyl-radicle; 4–9 times wider than hypocotyl-radicle; entirely concealing hypocotyl-radicle, or partially concealing hypocotyl-radicle; foliaceous (and occasionally laciniate); thin; undulate (ruminate); ruminate; with apices bi lobed; with margins separate; basally cordate; equal in size; not punctate dotted. Hypocotyl-radicle moderately developed; straight; not thickened.
Distribution
Old World. Africa (Madagascar).
Notes
Often known as Rhopalocarpaceae. Goldberg (Not scored): seed initally enclosed in a translucent glutinous mass. Cotyledons separated right and left from one another like Juglans.
Weed information
No USA noxious weeds.
Listed seeds
No ASOA or ISTA listed seeds.
Accepted genera
Dialyceras Capuron -- Rhopalocarpus Bojer
References specific to this family
Cronquist page 313. Leroy, J.-F. 1973. Recherches sur la spéciation et l'endémisme dans la flore Malgache. III. Note sur le genre Dialyceras R. Cap. ( Sphaerosepalacées). Adansonia, sér. 2, 13:37–53.
General references
Baillon, H.E. 1866–95. Histoire des plantes, 13 vols. Hachette and Co., Paris, Cronquist, A. 1981. An integrated system of classification of flowering plants, 1,262 p. Columbia University Press, New York, 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, 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
Poor fruit and seed illustrations. Disseminule illustration(s): fruit, or seed, or embryo. Fruit illustration(s): Goldberg, Baillon. Seed illustration(s): Baillon. Embryo illustration(s): Baillon.
• Fruit. 1 of 3. Rhopalocarpus lucidus Bojer: fruiting head with some dehisced fruits. • Seed. 2 of 3. Rhopalocarpus lucidus Bojer: seed. • Embryo. 3 of 3. Rhopalocarpus thouarianus Baill.: 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’.
