76. Krigia Schreber, Gen. Pl. 2: 532. 1791.
Dwarf dandelion [For David Krieg, 16??–1713, plant collector in Maryland and Delaware]
Kenton L. Chambers, Robert J. O’Kennon
Apogon Elliott; Cymbia (Torrey & A. Gray) Standley; Cynthia D. Don; Serinia Rafinesque; Troximon Gaertner
Annuals or perennials, 3–75 cm; taprooted, fibrous-rooted, or (in K. dandelion) with rhizomes bearing globose tubers. Stems 1–50+, usually erect, rarely decumbent, scapiform or branched distally, glabrous or sparingly villous (proximally). glandular-villous (especially distally). Leaves mostly basal, sometimes cauline; petiolate (petioles often winged); blades linear to lanceolate, oblanceolate, or spatulate, margins entire, denticulate, or irregularly pinnately lobed, apices acute to obtuse (faces glabrous or glandular-villous, usually glaucous in K. dandelion and K. biflora); distal cauline usually slightly reduced to bractlike. Heads borne singly. Peduncles not distally inflated, ebracteate (from rosettes and from axils of cauline leaves or bracts). Calyculi 0. Involucres turbinate to campanulate, 2–12 mm diam. Phyllaries (4–)5–18 in 1–2 series, (sometimes reflexed in fruit) linear-lanceolate to ovate, equal, herbaceous, apices acute (faces glabrous). Receptacles flat or low-convex, pitted. glabrous, epaleate. Florets 5–60; corollas yellow to orange (equaling or surpassing phyllaries). Cypselae brown or reddish brown, columnar, obconic, barrel-shaped, or fusiform, not beaked, nerves or ribs 10–20, glabrous ; pappi 0, or persistent, often fragile, usually in 2 series, distinct, outer of 5+, yellowish or brownish scales, inner of 5–45, barbellulate bristles (pappi 0 in K. cespitosa, 0 or 1 series of tiny scales in K. wrightii). x = (4) 5 (6, 9).
Species 7 (7 in the flora): North America, ne Mexico.
Krigia is diverse and limited to North America. On molecular evidence, it stands apart from other clades of Cichorieae and is best placed as a monotypic subtribe (J. Lee et al. 2003; Lee and B. G. Baldwin 2004). Early studies classified the pappose and epappose species as different genera. A unified view of the genus was taken by L. H. Shinners (1947), and this has been supported by recent morphologic and molecular studies (K. J. Kim and T. J. Mabry 1991; Kim and B. L. Turner 1992; Kim et al. 1992b, 1992c; Kim and R. K. Jansen 1994). The most common base number is x = 5, with lower and higher numbers having arisen through dysploidy, autoploidy, and both ancient and recent alloploidy (K. L. Chambers 1965, 2004; A. S. Tomb et al. 1978; C. C. Chinnappa 1981; Kim and Turner).
SELECTED REFERENCES
Chambers, K. L. 2004. Taxonomic notes on Krigia (Asteraceae). Sida 21: 225–236. Chinnappa, C. C. 1981. Cytological studies in Krigia (Asteraceae). Canad. J. Genet. Cytol. 23: 671–678. Kim, K. J. et al. 1992b. Evolutionary implications of intraspecific chloroplast DNA variation in dwarf dandelions (Krigia–Asteraceae). Amer. J. Bot. 79: 708–715. Kim, K. J. et al. 1992c. Phylogenetic and evolutionary implications of interspecific chloroplast DNA variation in Krigia (Asteraceae-–Lactuceae). Syst. Bot. 17: 449–469. Kim, K. J. and R. K. Jansen. 1994. Comparisons of phylogenetic hypotheses among different data sets in dwarf dandelions (Krigia, Asteraceae): Additional information from internal transcribed spacer sequences of nuclear ribosomal DNA. Pl. Syst. Evol. 190: 157–185. Kim, K. J. and T. J. Mabry. 1991. Phylogenetic and evolutionary implications of nuclear ribosomal DNA variation in dwarf dandelions (Krigia–Lactuceae–Asteraceae). Pl. Syst. Evol. 177: 53–69. Kim, K. J. and B. L. Turner. 1992. Systematic overview of Krigia (Asteraceae–Lactuceae). Brittonia 44: 173–198. Shinners, L. H. 1947. Revision of the genus Krigia Schreb. Wrightia 1: 187–206.
