Hilliardiella H. Rob., 1999 Figures 11 A–D; 12 A–D; 13 A; 14 A–H

Hilliardiella H. Rob. Proc. Biol. Soc. Wash. 112(1): 247. 1999. - Type: Vernonia pinifolia (Lam.) Less.

Webbia DC., Prodr. 5: 72. Oct 1836, nom. illeg., not Webbia Spach, Jun 1836.

Vernonia subsect. Hilliardianae S.B. Jones, Rhodora 83: 66. 1981. - Type: Vernonia oligocephala (DC.) Sch. Bip.

Descriptions.

Herbaceous perennials to 1 m tall; stems pilose, hairs unequally T-shaped. Leaves alternate; blades abaxially often densely canescent pilose. Inflorescence laxly to subdensely corymbiform-cymose. Heads short-pedunculate; involucres campanulate, bracts 25-40, in ca. 3-4 series, persistent; receptacle epaleaceous. Florets 12-20 in a head; corollas purple, outside with few to many slightly contorted T-shaped hairs; basal tube funneliform above, throat short, lobes linear; anther thecae not or shortly appendaged at base; apical appendages glabrous, with thin walls; style with basal node; style branches with acicular sweeping hairs. Achenes 4-5-costate, densely setuliferous, setulae scarcely divided at tips, idioblasts numerous, raphids elongate, carpopodia narrowly cylindrical; pappus bristles white, barbate, tenuous, subpersistent, outer series shortly lanceolate. Chromosome number of n = 9, 10, most reports n = 10 (Turner and Lewis 1965; Jones 1982).

Pollen grains sublophate, with continuous perforated tectum between colpi, tricolporate to poles, echinate (Fig. 14 A–H).

Notable secondary metabolites; acetones & sesquiterpene glaucolides/ hirsutanolides (Bohlmann and Jakupovic (1990, as Vernonia sutherlandii Harv., guaianolides, bisabolene derivatives (Bohlmann and Jakupovic 1990, as Vernonia hirsuta Sch. Bip. ex Walp. and Vernonia oligocephala (DC.) Sch. Bip. ex Walp.).