Vernonieae (Asteraceae) of southern Africa: A generic disposition of the species and a study of their pollen
Author
Robinson, Harold
Author
Skvarla, John J.
Author
Funk, Vicki A.
text
PhytoKeys
2016
60
49
126
http://dx.doi.org/10.3897/phytokeys.60.6734
journal article
http://dx.doi.org/10.3897/phytokeys.60.6734
1314-2003-60-49
FFC26762742EFFBDFFAD0867FFB3FFBB
576336
Erlangea Sch. Bip., 1853
Figures 7 A, B
; 8
A-C
Erlangea
Sch. Bip., 1853, Flora 36: 34. 1853. - Type:
Erlangea plumosa
Sch. Bip.
Resources.
Species treatment based on
Wild and Pope 1977
.
Descriptions.
Annual or short-lived perennial herbs; stems erect, branching near base; hairs on vegetative parts simple, uniseriate, multicellular, with a straight elongate apical cell. Leaves alternate, sessile or subsessile, pinnately veined with weak secondary veins, margins serrulate, apices obtuse. Inflorescence with single terminal head or laxly cymiform with narrowly pedunculate heads. Heads campanulate; involucral bracts 45-60 in 3-4 series, gradate, cuspidate apically, with distinct pale or reddish lateral margins, pilose to lanulose outside; receptacle convex, epaleaceous, with glabrous reticulum. Florets 50-75 or more in a head; corollas reddish, funnelform, with slender basal tube bearing small stipitate glands, throat shorter than lobes, lobes linear-lanceolate, with stiff hairs distally or apically; anther thecae short-acute with small sterile margin at base; apical appendage, oblong-ovate, glabrous, with thin cell walls; style base with nar
row
annuliform sclerified node; sweeping hairs acicular, at lowest level scarcely extending to top of shaft. Achenes shortly obconic, abruptly narrowed distally to insertion of corolla, 3-6-ribbed, setulae restricted mostly to broad ribs, setulae not split at tips, sides with scattered isolated idioblasts, raphids subquadrate or short oblong in dense inner layer of short to quadrate cells in achene wall; pappus of less than 20 easily deciduous barbellate bristles, bases narrow and weakly attached, distinct outer series not evident. Chromosome number n = 10 (
Turner and Lewis 1965
,
Nordenstam 1967
).
Pollen ca. 47
μm
in diameter in fluid, lophate, triporate, with group of polar lacunae, perforated tectum restricted to muri, bacculae centered at junctures of muri, leaving ogee-shaped gaps under the centers of the muri (Figs
8
A-C
).
Figure 7.
Photographs of
Erlangea
and
Ethulia
:
A-B
Erlangea misera
S. Moore, and
C-E
Ethulia conyzoides L.f. subsp. conyzoides
, note:
Ethulia
has no capillary pappus. See Appendix C for citation details.
Figure 8.
Scanning electron micrographs of acetolyzed echinolophate pollen of
Erlangea
and sublophate pollen of
Ethulia
.
A-C
Erlangea misera
(Oliv. & Hiern) S. Moore.
A
Poral view
B
Near polar view
C
Grain fragment.
D-F
Ethulia conzyoides
L.f.
D
Equatorial view, showing comparatively blunt spines
E
Lateral view
F
Grain fragment. (
D-F
Funk 12708
G
Petelot 4047
H
Lewis 6025
;
Ethulia
views from Robinson and Skvarla (2010)).
Notable secondary metabolites, eudesmanolide sesquiterpene lactones,
Bohlmann and Jakupovic 1990
, as
Erlangea remifolia
Wild & Pope).