Sphaerosepalaceae

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Content is from Kirkbride et al. 2006, without modification. 
Updates are forthcoming.

Taxonomy

Sphaerosepalaceae (Warburg) Tieghem ex Bullock 

Common name: Rhopalocarpus Family.

Number of genera: 2 genera.

Number of species (Mabberley 1997): 17 species.

Disseminule

Fruit (intact or entire).

Description

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; with 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 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; & 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; ellipsoidal. 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

General distribution: Old World.

Detailed distribution: 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.

References

Literature specific to this family: 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 & 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) & 1989 (monocots). Classification, evolution, and phylogeny of the familes of Dicotyledons. Smithsonian Contr. Bot. 58 for dicots (314 pp.) & 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, & J.H. Kirkbride, Jr. 1992 & 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, and Spjut, R.W. 1994. A systematic treatment of fruit types. Mem. New York Bot. Gard. 70:1–182.