Hilliardiella
Vernonia pinifolia
Webbia
Webbia
Vernonia subsect. Hilliardianae
Vernonia oligocephala
Vernonieae (Asteraceae) of southern Africa: A generic disposition of the species and a study of their pollen
Robinson, Harold
Skvarla, John J.
Funk, Vicki A.
PhytoKeys
2016
60
49
126
907CEC40-DCFD-71F5-EF94-2347EFE0C3A3
H. Rob., 1999
H. Rob.
1999
Magnoliopsida
Asteraceae
Hilliardiella
CoL
Plantae
Hilliardiella
Asterales
23
72
Tracheophyta
genus
HilliardiellaH. Rob. Proc. Biol. Soc. Wash. 112(1): 247. 1999. - Type: Vernonia pinifolia(Lam.) Less. WebbiaDC., Prodr. 5: 72. Oct 1836, nom. illeg., not WebbiaSpach, Jun 1836. Vernonia subsect. HilliardianaeS.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). Figure 11.Photographs of Hilliardiella. A-B Hilliardiella aristata(DC.) H. Rob. C-D Hilliardiella flanaganii(E. Phillips) H. Rob. See Appendix C for citation details. Figure 12.Photographs of Hilliardiella oligocephala(DC.) H. Rob.: AHabit BClose up of head CCharacteristic leaf Dheads in fruit. Note: discolorous leaves are characteristic of some but not all species of Hilliardiella. See Appendix C for citation details. Figure 13.Illustrations Hilliardiella, Linzia, Parapolydora, and Vernonella: A Hilliardiella capensis(Houtt.) H. Rob., Skvarla & V.A. Funk B Linzia glabraSteetz in Peters, note: characteristic teeth on involucral bracts C Parapolydora gerrardii(Harv.) H. Rob D Vernonella africanaSond. See Appendix C for citation details. Figure 14.Scanning electron micrographs of acetolyzed pollen from two collections of Hilliardiella capensisemphasizing spine variations. The surface seems to vary between sublophate and slightly echinolophate. APolar view BEquatorial view CLateral view DPolar view EEquatorial view FSubpolar view GFragmented pollen surface HGrain fragment showing structural support of spine. ( A-C Bayliss BS3686 D-H Gentry & Barolas 18914). Notablesecondary metabolites; acetones & sesquiterpene glaucolides/ hirsutanolides ( Bohlmann and Jakupovic (1990, as Vernonia sutherlandiiHarv., guaianolides, bisabolene derivatives ( Bohlmann and Jakupovic 1990, as Vernonia hirsutaSch. Bip. ex Walp. and Vernonia oligocephala(DC.) Sch. Bip. ex Walp.).