17. Graptopetalum Rose, Contr. U.S. Natl. Herb. 13: 296, fig. 55, plate 52. 1911.
[Greek graptos, marked, and petalon, leaf, alluding to petals]
Reid V. Moran
Herbs [or shrubs], perennial, not viviparous, 2.5-3.5 dm, glabrous or papillose. Stems erect, branched or unbranched, succulent; floral stems annual, axillary, overtopping rosette, with scattered smaller leaves. Leaves persistent, in dense, basal rosettes, alternate, sessile, subclasping [narrowed] basally; blade cuneate- or rhombic-oblanceolate or -obovate, laminar or semiterete, 2-10 cm, succulent, base not spurred, margins entire; with [1] several veins entering margins. Inflorescences lateral, flat or paniculate cymes. Pedicels present. Flowers (fetid), erect, 5-8-merous; sepals distinct, ± alike in size; petals spreading or slightly reflexed from middle, connate basally, [mostly] pale yellow irregularly dotted and red-banded in distal 1/2; calyx and corolla not circumscissile in fruit; nectaries flabellate; stamens [as many] 2 times as many as sepals; filaments adnate to corolla base, (becoming reflexed); pistils erect, connate basally; ovary base narrowed; styles 2+ times shorter than ovaries. Fruits mostly erect. Seeds narrowly ovoid, finely grooved, papillose. x = 30-35.
Species 15 (2 in the flora): Arizona, Mexico.
From cytological studies (C. H. Uhl 1970, 1992), Graptopetalum belongs to a large comparium with Echeveria, Lenophyllum, Villadia, and others, but not including Dudleya.
SELECTED REFERENCES Acevedo-Rosas, R. et al. 2004. Phylogenetic relationships and morphological patterns in Graptopetalum (Crassulaceae). Brittonia 56: 185-194. Acevedo-Rosas, R. et al. 2004b. A molecular phylogenetic study of Graptopetalum (Crassulaceae) based on ETS, ITS, rfpl16, and trnL-F nucleotide sequences. Amer. J. Bot. 91: 1099-1104. Uhl, C. H. 1970. Chromosomes of Graptopetalum and Thompsonella. Amer. J. Bot. 57: 1115-1121.
