Comparison of nightshades (Solanum spp.): with spiny prickles and star-shaped hairs

*Prickles sometimes sparse or absent

	life cycle/habit	underground structures	flower diameter/color	mature leaves length/shape/margins	mature berry diameter/color	star-shaped hairs (20x magnification)	other characteristics
horsenettle Solanum carolinense	perennial erect to sprawling, to 1 m tall	deep creeping root system	20-30 mm pale violet or white	5-15 cm ovate; wavy to 5-7(9)-lobed £ halfway to midrib	8-20 mm yellow	yellowish, sessile & short-stalked, rays mostly 5-7, central ray ³ radiate rays	flower clusters often raceme-like; seeds yellow to orange-brown, 1.5-3 mm long; prickles yellowish
robust horsenettle* Solanum dimidiatum	perennial erect (to sprawling), to 1 m tall	deep creeping root system	30-50 mm purple, violet, (white)	8-15 cm ovate; wavy to 5-7(9)-lobed ³ halfway to midrib	25-30 mm bright yellow	yellowish, sessile & short-stalked, rays mostly 6-8, central ray £ radiate rays	flower clusters branched or forked; seeds tan, 3-4 mm long; prickles yellowish
silverleaf nightshade* Solanum elaeagnifolium	perennial erect, to 1 m tall	deep creeping root system	20-30 mm purple to blue, sometimes pale	2-15 cm lanceolate to oblong; barely wavy to shallow wavy-lobed	8-15 mm greenish-yellow, to brownish-orange	silvery white, minute, +/- sessile, rays mostly 9-14, shield-like at center, central ray usually << radiate rays	flower clusters raceme-like; seeds +/- dark yellow-brown, 2.5-3.5 mm long; prickles tan to reddish
lanceleaf nightshade* Solanum lanceolatum	soft-wooded shrub erect, to 5 m tall	woody crown, deep creeping root system	25-30 mm blue-purple to light violet	3-15 cm lanceolate to broadly ovate; entire to coarse wavy-lobed ~ halfway to midrib	7-15 mm yellowish-orange	+/- straw-colored, minute, sessile & stalked, rays mostly 5-9, central ray £ radiate rays	berries several per cluster; calyx not prickly; hairs velvety dense on leaf under surfaces and stems
white-margined nightshade Solanum marginatum	soft-wooded shrub erect, to 2 m tall	woody crown, taproot & lateral roots, seldom creeping	15-30 mm white, with purple center	10-18 cm broadly ovate; shallow coarse wavy-lobed, whitish from hairs	35-50 mm pale to deep yellow	white, +/- iridescent, minute, stalked, rays mostly 7-9, central ray usually @ radiate rays	berries often single; calyx prickly; seeds yellowish to light brown, 2-4 mm long; hairs very dense on leaf margins & lower surfaces
buffalobur Solanum rostratum	annual erect, to 1 m tall	tap-root & lateral roots	20-35 mm yellow	5-15 cm (ob)ovate; lobed to midrib, lobes irregular wavy-lobed	9-12 mm completely enclosed by a spiny bur-like calyx	yellowish, sessile & stalked, rays mostly 6-8, central ray often ³ radiate rays	some hairs glandular; 1 anther larger; seeds dull dark red-brown to black, 2-3 mm long; prickles yellowish
sticky nightshade Solanum sisymbriifolium	annual to short-lived perennial erect, to 1.5 m tall	tap-root & lateral roots	25-30 mm pale blue to white	4-15 cm ovate; lobed halfway to all the way to midrib, lobes shallow wavy-toothed to acute-lobed	10-20 mm red, ~ half to mostly enclosed by prickly calyx	white to yellow, +/- sparse, stalked, rays mostly 4-6, central ray often glandular and > radiate rays	many glandular hairs; seeds orange-yellow, ~ 2 mm long; prickles to 15 mm long, tan or brown to reddish;