2. Lycium L. (wolfberry)

Plants shrubs, usually armed with short thorns 5–20 mm long at some nodes. Stems 1–2(–4) m long, arched or spreading, sometimes climbing, many-branched, glabrous. Twigs gray to yellowish tan, the winter buds ovoid to nearly globose, with 3 or more appressed, glabrous scales. Leaves alternate or appearing fasciculate at the tips of very short branches, sessile or short-petiolate, the petiole often mostly winged. Leaf blades, simple, unlobed, lanceolate to elliptic, oblanceolate, ovate, or rhombic-ovate, rounded or more commonly angled or slightly tapered to a bluntly or sharply pointed tip, angled or tapered at the base, the margins otherwise entire or rarely minutely scalloped or slightly wavy, the surfaces green to grayish green, glabrous. Inflorescences axillary, of solitary flowers or small clusters of 2 or 3 flowers. Flowers mostly spreading, the stalks often slightly curved upward, thickened toward the tips. Calyces 2–5-lobed, fused to the midpoint or slightly less, when fewer than 5 lobes present then the lobes frequently few-toothed, bell-shaped to broadly tubular, rounded at the base, lacking basal auricles, persistent intact at fruiting, not or only slightly enlarged, not balloonlike or papery, closely cupped around (and often ruptured by) the base of the fruit, not angled. Corollas narrowly bell-shaped to more or less trumpet-shaped, the 5(6) lobes spreading, not appearing pleated in bud, the tube white to pale green, sometimes pinkish- or pale purplish-tinged, the lobes light pink to pale purple or lilac, the throat usually with a network of darker lines. Stamens with the relatively long filaments attached at or near the tip of the corolla tube, usually densely hairy basally, the anthers free, dehiscent longitudinally, exserted, light yellow. Ovary 2-locular, the style exserted, about as long as to slightly longer then the stamens, the stigma green. Fruits berries, 8–20 mm long, juicy, ellipsoid to slightly ovoid or obovoid, 2-locular, red to reddish orange, with several to numerous seeds, lacking stony granules among the seeds. Seeds 2–3 mm in longest dimension, somewhat flattened, circular to oval in outline, notched at the attachment point, lacking wings, the surface finely pitted, yellowish brown. About 80 species, North America, Central America, South America, Europe, Africa, Asia south to Australia.

Most species of Lycium are native to the New World, but a minority of species are widespread in the Old World. The species in Missouri are introductions from Eurasia that formerly were popular in cultivation in the Midwest, but are no longer as widely sold by plant nurseries. The fruits of L. barbarum and L. chinense are marketed by the health food industry under the name goji berry. They are purported to be rich in antioxidants and are sold as a general immune system booster and tonic. Both have a long history of medicinal use in China.

The two species reported as escapes from cultivation in Missouri require further study. Some American authors have gone so far as to treat them as a single species (Gleason and Cronquist, 1991). None of the specimens is a perfect match for the morphology displayed by L. chinense in its native range, and there appears to be less than perfect correlation between leaf shape, calyx lobing, and pubescence characters ascribed to L. chinense in the introduced populations. Because our plants are derived from horticultural materials, it is likely that they are atypical as a result of breeding and selection of cultivars.

Capsicum annuum L. (bird pepper) is a species that is frequently cultivated for its brightly colored fruits. The genus Capsicum is also the source of the chili peppers used for food and spice. For a lucid, nontechnical discussion of chili peppers, see Heiser (1969). Occasionally when plants or fruits are discarded or added to compost piles, seeds germinate. The spontaneous forms of the species, whether wild within the native range or escaped elsewhere, have been referred to the ssp. annuum. However, although there two specimens have been collected in noncultivated situations in the state, there is no evidence that the species ever reproduces successfully in the wild in Missouri. A specimen at the University of Missouri herbarium collected by David Dunn in October, 1966, documents a solitary plant of C. annuum growing as a volunteer in a student housing area in Columbia (Boone County). The plant did not reappear during subsequent years. Similarly, a plant was collected in 1993 by James Miller (then of the Missouri Botanical Garden) on a gravel bar of the Jacks Fork River in Shannon County. Such rare individuals can grow from seeds accidentally scattered into a highly disturbed habitat, but show no evidence of persistence in subsequent years. The genus Capsicum is superficially similar to Lycium, but lacks thorns and has saucer-shaped corollas. Although within its native range C. annuum is a shrub to 3 m or more tall, plants sold in the horticultural industry in the midwestern United States generally are grown as annuals.