Herbs, subshrubs, or shrubs. Stems mostly fleshy. Leaves alternate, opposite, or verticillate, usually simple; stipules absent; leaf blade entire or slightly incised, rarely lobed or imparipinnate. Inflorescences terminal or axillary, cymose, corymbiform, spiculate, racemose, paniculate, or sometimes reduced to a solitary flower. Flowers usually bisexual, sometimes unisexual in Rhodiola (when plants dioecious or rarely gynodioecious), actinomorphic, (3 or)4-6(-30)-merous. Sepals almost free or basally connate, persistent. Petals free or connate. Stamens as many as petals in 1 series or 2 × as many in 2 series. Nectar scales at or near base of carpels. Follicles sometimes fewer than sepals, free or basally connate, erect or spreading, membranous or leathery, 1- to many seeded. Seeds small; endosperm scanty or not developed.
Annual, biennial, or perennial herbs or shrubs [rarely scandent], succulent. Stems mostly alike and all potentially flowering, (flowering stems annual, axillary, overtopping primary stem). Leaves usually persistent, sometimes deciduous or caducous, cauline or sometimes in dense basal rosettes, alternate, opposite, or whorled, simple (pinnate in Bryophyllum), (heteromorphic in Dudleya, Echeveria, Graptopetalum); stipules absent; petiole usually absent; blade margins usually entire, sometimes toothed or lobed. Inflorescences terminal or axillary, spikes, thyrses, or mostly cymes, branches commonly cincinni (scorpioid cymes) and at first commonly coiled, or rarely flowers solitary. Flowers bisexual (sometimes unisexual in Rhodiola), radially symmetric (except sometimes calyx); perianth and androecium hypogynous or weakly perigynous; hypanthium present; sepals (3-)4-5(-12)[-30+], distinct or connate basally (or into tube); petals (3-)4-5(-12)[-30+], distinct or connate basally or sometimes into tube, margins entire (fimbrillate in Jovibarba, crenate in Phedimus); nectaries as scales at base of carpels; stamens as many as sepals or 2 times as many and in 2 series, antipetalous if in 1 series, free or adnate to corolla base (or tube); anthers dehiscent longitudinally and laterally; pistils (3-)4-5(-12)[-30+] [rarely fewer than sepals], mostly distinct or nearly so, (3-)4-5(-12)[-30+]-carpellate; ovary superior or semi-inferior, 1-locular; placentation submarginal; ovules anatropous, bitegmic, crassinucellate or tenuinucellate; styles (3-)4-5(-12)[-30+], terminal, distinct; stigmas (3-) 4-5(-12)[-30], terminal, capitate. Fruits usually whorls of follicles, each dehiscent along adaxial suture, rarely whorls of flimsy 1-seeded utricles (Sedella) or capsules of basally connate pistils (Diamorpha, Jovibarba). Seeds 1-20+ per carpel, brownish, fusiform or ellipsoid; embryo straight; endosperm oily, scant.
Herbs and undershrubs, usually succulent; leaves opposite or alternate, exstipulate
Seeds mostly minute, usually with fleshy endosperm; embryo straight
Fruit follicular, membranous or leathery, often surrounded by the persistent membranous corolla, opening on the adaxial side
Stamens as many or twice as many as the petals, if few then alternate with the petals, slightly perigynous; filaments free; anthers 2-celled, introrse, dehiscing longitudinally
Petals the same number as the sepals, free or variously connate, hypogynous
Carpels superior, the same number as the petals free or united at the base, 1-celled; ovules many or rarely few, inserted on the adaxial suture; styles short or elongated
SELECTED REFERENCES Berger, A. 1930. Crassulaceae. In: H. G. A. Engler et al., eds. 1924+. Die natürlichen Pflanzenfamilien..., ed. 2. 26+ vols. Leipzig. Vol. 18, pp. 352-485. Britton, N. L. and J. N. Rose. 1903. New or Noteworthy North American Crassulaceae. New York. [Preprinted from Bull. New York Bot. Gard. 3: 1-45. 1903.] Britton, N. L. and J. N. Rose. 1905. Crassulaceae. In: N. L. Britton et al., eds. 1905+. North American Flora.... 47+ vols. New York. Vol. 22, pp. 7-74. Eggli, U., ed. 2003. Illustrated Handbook of Succulent Plants. Crassulaceae. New York. Ham, R. C. H. J. van and H. ’t Hart. 1994. Phylogenetic relationships in the Crassulaceae inferred from chloroplast DNA restriction-site variation. In: R. C. H. J. van Ham. 1994. Phylogenetic Implications of Chloroplast DNA Variation in the Crassulaceae. Utrecht. Pp. 81-103. Ham, R. C. H. J. van and H. ’t Hart. 1998. Phylogenetic relationships in the Crassulaceae inferred from chloroplast DNA restriction-site variation. Amer. J. Bot. 85: 123-134. ’t Hart, H. 1995. Infrafamilial and generic classification of the Crassulaceae. In: H. ’t Hart and U. Eggli, eds. 1995. Evolution and Systematics of the Crassulaceae. Leiden. Pp. 159-172. Knapp, U. 1994. Skulptur der Samenschale and Gliederung der Crassulaceae. Bot. Jahrb. Syst. 116: 157-187. Mauritzon, J. 1933. Studien über die Embryologie der Familien Crassulaceae und Saxifragaceae. Lund. Mayuzumi, S. and H. Ohba. 2004. The phylogenetic position of eastern Asian Sedoideae (Crassulaceae) inferred from chloroplast and nuclear DNA sequences. Syst. Bot. 29: 587-598. Mort, M. E. et al. 2001. Phylogenetic relationships and evolution of the Crassulaceae inferred from matK sequence data. Amer. J. Bot. 88: 76-91. Ohba, H. 1978. Generic and infrageneric classification of the Old World Crassulaceae. J. Fac. Sci., Univ. Tokyo, Sect. 3, Bot. 12: 139-198. Quimby, M. W. 1939. The Floral Morphology of the Crassulaceae. Ph.D. dissertation. Cornell University. Spongberg, S. A. 1978. The genera of Crassulaceae in the southeastern United States. J. Arnold Arbor. 59: 198-248. Uhl, C. H. 1963. Chromosomes and phylogeny of the Crassulaceae. Cact. Succ. J. (Los Angeles) 35: 80-84.