Parapolydora H. Rob., 2005

Robinson, Harold, Skvarla, John J. & Funk, Vicki A., 2016, Vernonieae (Asteraceae) of southern Africa: A generic disposition of the species and a study of their pollen, PhytoKeys 60, pp. 49-126 : 87-89

Parapolydora H. Rob., 2005 Figures 13 C ; 20 A–C ; 21 A–F

Parapolydora H. Rob., Phytologia 87(2): 78. 2005. - Type: Vernonia fastigiata Oliv. & Hiern.

Descriptions.

Perennial herbs 0.2-1.0 m tall; from slender prostrate or creeping stem or rhizome, erect stems with few to many ascending branches, five-ribbed, sides with numerous glandular dots, glabrous or finely and sparsely puberulous with some simple multiseptate hairs, and some one-armed L-shaped hairs with stalk near one end as in Polydora . Leaves alternate, linear to narrowly elliptic-lanceolate, venation pinnate with short, ascending, secondary veins weakly prominulous below, surfaces concolorous, glandular dots more numerous below, sparsely puberulous. Inflorescences of long-pedunculate heads terminal on leafy stems and branches; involucres broadly campanulate to subglobose; involucral bracts 110-130 in ca. six series, persistent, gradate, from 2-12 mm long, bases of bracts oblong, pale, appressed, covered with dense pale tomentum, bracts distally constricted into long glabrous, often reflexed awn, darkened along costa near base of awn; receptacle epaleaceous, alveolate. Florets 45-50 in a head; corollas lavender, without hairs, basal tubes narrowly funnelform, glabrous, throats about as long as linear lobes, few glands on throat and glands clustered at lobe tips; thecae of anthers without tails at base; apical appendages ovate-lanceolate, glabrous, with thin-walled cells; style base with distinct annular node; style branches with long acicular sweeping hairs scarcely extending below base of branches. Achenes weakly 8-10-veined, with setulae becoming long and uniseriate from near middle or near base, rarely with one long cell and one short cell, idioblasts numerous from base to top of achene, raphids elon gate; pappus white or grayish, inner series of many barbellate bristles, not broadened at tips, outer series of numerous, short, linear scales. Chromosome number unknown.

Pollen ca. 50 μm in diam., sublophate, echinate (Type A), tricolporate, sub-echinolophate (Fig. 21 A–D ).

Most notable secondary metabolites, sesquiterpene nerolidol derivatives ( Bohlmann and Jakupovic (1990).

Figures

Figure 13. Illustrations Hilliardiella, Linzia, Parapolydora, and Vernonella: A Hilliardiella capensis (Houtt.) H. Rob., Skvarla & V. A. Funk B Linzia glabra Steetz in Peters, note: characteristic teeth on involucral bracts C Parapolydora gerrardii (Harv.) H. Rob D Vernonella africana Sond. See Appendix C for citation details.

Figure 20. Photographs of Parapolydora and Polydora: A-C Parapolydora fastigiata (Oliv. & Hiern in Oliv.) H. Rob. D-F Polydora poskeana (Vatke & Hildebrandt) H. Rob. See Appendix C for citation details.

Figure 21. Scanning electron micrographs of acetolyzed sublophate-echinolophate pollen grains of two collections of Parapolydora fastigata (Oliv. & Hiern in Oliv.) H. Rob. A Polar view B Equatorial view showing thickened echinolophate ridges along aperture C-D Lateral views showing highly perforate meandering lophal ridges E Grain fragment showing thickened columellae underneath two spine regions F Grain fragment showing perforate lacunar exine with close parallel proximity to foot layer between thickened columellae supporting spines. (A Pienaar 1073 B-F Seydel 4023).