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;