Key to Wisconsin Physalis

Author: Theodore S. Cochrane

• 1a.Corolla distinctly lobed, white or whitish, sometimes with 5 green spots within; fruiting calyx bright scarlet, retaining its color when dried P. alkekengi

• 1b.Corolla scarcely lobed, yellow or yellowish green with prominent, brownish or purplish basal spots or these coalesced into a ring; fruiting calyx green to straw-colored, drying brown 2

• 2a.Plant annual, ± tap-rooted (roots likely present on herbarium specimens); corolla 5–11 mm long (or to 15 mm in P. philadelphica); anthers blue-violet; fruiting pedicels < 1 cm long 3

• 2b. Plant perennial from deep-seated rootstocks (subterranean parts usually missing from collected specimens); corolla 9–18 (–20) mm long; anthers yellow or edged or tinged with blue; fruiting pedicels 1–3 cm long 4

• 3a.Leaves lanceolate or narrowly elliptic, entire to sinuate-toothed; plant glabrous or glabrate (except upper parts strigillose); anthers (1.9–) 2.3–3.6 mm long, coiled after dehiscence P. philadelphica

• 3b.Leaves cordate-ovate, coarsely angulate-toothed; plant villous, the long hairs eglandular or in part glandular, the short hairs mixed with sessile glands; anthers 1.5–2 mm long, not coiled P. grisea

• 4a. Herbage densely villous with short, fine, usually gland-tipped hairs, these mixed in varying proportions with multicellular flattened hairs 1–2 mm long; leaves ovate to rhombic, broadly rounded to truncate or subcordate at the base P. heterophylla

• 4b.Herbage glabrous or with short, ± stiff, non-glandular hairs; leaves narrowly ovate to oblong, elliptic, or lanceolate, seldom subrhombic or oblanceolate, cuneate at the base 5

• 5a. Stems, especially younger parts, with sparse antrorse hairs or nearly glabrous; calyx nearly glabrous or strigillose in 10 longitudinal lines along the principal veins P. longifolia

• 5b. Stems, especially branches, with reflexed or retrorse hairs, sometimes mixed with spreading hairs; calyx hirsutulous over the whole surface with retrorse or recurved hairs or these mixed with some longer spreading hairs P. virginiana

The fruit is much like a miniature tomato in color, shape, and structure. It is likewise non-poisonous, albeit not always edible, and loosely enclosed within a large, bladder-like husk derived from the calyx. Sizes and shapes of plant organs and characters of indumenta may be variable or may occur also in other taxa or intergradient specimens, allowing for differences of taxonomic interpretation as to species boundaries. Ordinarily, however, our species are not difficult to distinguish.