A Revision of Heterotheca sect. Phyllotheca (Nutt.) Harms (Compositae: Astereae): The Prairie and Montane Goldenasters of North America. University of Waterloo Biology Series No. 37 by John C. Semple

2 Pages·1996·1 MB·English

by  Review By: C John Burk

RHODORA,
Vol. 98, No. 894, 218-219, 1996
pp.
BOOK
REVIEW
A
Semplc, John
C. 1996. Revision Heterotheca Phyllo-
r;/ sect.
Harms
theca (Niitt,) (Compositae: Astereae): The Prairie
Montane
afid Goldenasters of North America, University of
Waterloo Biology Series No. 37. 164 $15.00 plus
pp., illus.
$5.00 shipping and handling (paper). PubHshed by U. W.
Biology Department Wa-
Series, of Biology, University of
N2L
terloo, Waterloo, Ontario, Canada 3G1.
The
goldenasters (golden and camphorweeds
asters) are yel-
summer
low-flowered, and fall-blooming, annual and perennial
herbs ranging eastern North America from Massachusetts
in the
coastal plain south into Texas and the west from Canada
in to
southern Mexico. Their generic circumscriptions have been "in
turmoil" (Semple's phrase) since the early 1950s. Thus the only
New
somewhat
widespread England
Chrysopsis
species, falcata
(Pursh) Ell. in the great mid-century floras of the region, became
fi
/.
North America. This very well done monograph would be
useful
alone introductory expounding
for sections the nomenclatural
its
complex
history of group.
this
According Semple, most North American
to goldenasters are
among
divided Chrysopsis Heterothcca
(9 species), (28 species),
and
Pityopsis species). Pityopsis and Chrysopsis centered
(7 are
in the southeastern United States while Heterotheca most abun-
is
dant and diverse in the west. Within the United States, Hetero-
theca sect. Phyllotheca occurs largely in the prairie and montane
regions west the Mississippi, although H. camporiim (Greene)
o\:
camporum
Shinners var. extends through the Prairie Peninsula
camporum
region into western Indiana and H.
glandulissi-
var.
mum
Semple number
has recently spread to a of eastern
sites.
Perhaps surprisingly, most of the twenty species Phyl-
in sect.
and
lotheca have been
their varieties historically included within
Chrysopsis villosa (Pursh) Nutt., characterized by H. A. Gleason
in 1952 as complex and poorly understood aggregate
species,
''a
of uncertain limits," often distinctive varieties ''connected by
its
numerous
Semple,
intergrades." in revising the group, has taken
on daunting and
a task, at the very least has established a coherent
system widespread and
for a protean assemblage, with clear de-
218
Book Review 219
1996]
scriptions of taxa. His laxonomic treatment includes keys to
its
the three sections and 28 species of Heterotheca and their vari-
summary
general of section PhyUotheca, and accounts of
eties, a
maps
each of species and varieties. Included are range in suf-
its
among
ficient detail to delight the biogeographers us and black
and white illustrations showing growth habit, leaves, and, in very
fine detail, the reproductive structures of each taxon. There are
also lengthy of cited specimens and narrative discussions
lists
with notes on aberrant or atypical forms, potentially very useful
information of a sort too quickly glossed over in broad floristic
treatments. Semple warns the reader early-on that the taxa within
Phyllotheca are defined by combinations of rather than by
traits
and most
single diagnostic features that within species, leaf in-
dument
(often featured prominently within his keys) varies in a
gradient from taxa possessing numerous hairs and few or no
many
glands to closely related forms with few hairs and glands.
Indeed, within some specimens, the indument of the basal leaves
may
vary sharply from that of the upper leaves, reflecting differ-
ent environmental conditions the time of leaf formation.
at
Thus, suspect that despite Dr. Semple's efforts, because of
its
I
Phyllotheca continue present
inherent variability, section will to
difficulties for field biologists. Hence, whether or not his treat-
ment, which proposes new names and combinations within
six
section Phyllotheca alone, will survive the inevitable revisions of
much
open
the 21st Century, very an question. If his structure
is
time dismantled, he has nonetheless brought together here
in
is
building blocks shape another.
the to
—
C. John Burk, Department o^ Biological Sciences, Smith Col-
MA
Northampton, 01063.
lege,