59. Antennaria Gaertn. (pussytoes)
(Bayer, 1993)
Plants
perennial, dioecious, fibrous-rooted, with more or less leafy stolons (with
rhizomes elsewhere), often forming colonies. Flowering stems erect or
ascending, moderately to densely woolly, the hairs sometimes becoming thinner
with age. Basal leaves persistent at flowering, much larger than the lower stem
leaves. Stem leaves several, sessile, the margins entire, both surfaces densely
white-woolly or the upper surface sparsely hairy to glabrous. Inflorescences
terminal, relatively dense clusters, occasionally appearing as small panicles,
flat-topped to more commonly rounded, the individual heads mostly
short-stalked. Heads with all staminate or all pistillate florets, the
pistillate heads very rarely with a few central staminate florets, the
staminate heads with the involucre usually slightly shorter than those of the
pistillate ones. Involucre narrowly ovoid to narrowly bell-shaped at flowering,
becoming broadly bell-shaped or funnel-shaped at fruiting or when pressed, the
bracts in 5–8 overlapping series, appressed when young, often somewhat
spreading with age or upon drying, those of the outer few series shorter and
ovate, densely woolly, with short, broadly pointed tips; those of the inner few
series noticeably longer and narrowly lanceolate, sparsely woolly, with
elongate, tapered, thin tips, green (turning straw-colored or brown with age)
toward the base, white to translucent toward the tip, usually at least somewhat
purplish-tinged. Receptacle flat or convex, naked. Corollas slender, those of
the staminate florets shorter than those of the pistillate florets, tubular or
those of the staminate florets narrowly trumpet-shaped, white or yellow,
sometimes reddish- or purplish-tinged. Pappus of the pistillate florets of
numerous slightly longer capillary bristles, that of the staminate florets of
fewer slightly shorter bristles, the bristles all or mostly free and shed
individually or in small groups, minutely toothed and sometimes slightly
expanded and narrowly club-shaped at the tip. Fruits 1.0–1.5 mm long, narrowly
elliptic-obovoid, not or only slightly flattened, the surface appearing pebbled
or roughened with minute papillae, brown to olive brown. Seventy to 100
species, North America, South America, Europe, Asia.
Species recognition
in Antennaria is difficult because hybridization, polyploidy, and
apomixis are widespread among the North American taxa. Fortunately, relatively
few taxa have been documented thus far from Missouri. The classification of Bayer and
Stebbins (1982) represents a practical compromise between the need to provide
taxonomic recognition of the polyploid hybrid derivatives as separate species
from their diploid progenitors and the problems for identification that would
be created if each of the races resulting from similar but independent
hybridization events were attempted to be recognized. See Cronquist (1946) for
a more taxonomically conservative interpretation.
Bayer and
Stebbins (1982) mapped the occurrence of A. solitaria Rydb. from
southeasternmost Missouri
without citation of locality or specimens. Randall Bayer (then of the University of Alberta)
kindly checked his notes and was unable to substantiate the report, thus it is
excluded from the Missouri
flora for now. It does occur in adjacent portions of Arkansas,
Kentucky, and Tennessee,
so it should be searched for in Missouri.
Antennaria solitaria differs from other members of the genus in
consistently having a single relatively large head (involucre 8–14 mm long) at
the tip of each flowering stem. Vegetatively, it resembles A. parlinii
in having broad basal leaves with multiple main veins, and, in fact, A.
solitaria is one of the diploid sexual progenitors in the A. parlinii
complex.