Lactuca virosa |
Lactuca sativa |
|
---|---|---|
bitter lettuce, great lettuce, poison wild lettuce, tall lettuce, wild lettuce |
cultivated lettuce, garden lettuce |
|
Habit | Biennials, 20–120(–200+) cm. | Annuals or biennials, (15–)30–70(–100+) cm. |
Leaves | on proximal 1/2–2/3 of each stem; blades of undivided cauline leaves obovate to spatulate, margins denticulate, midribs usually prickly-setose. |
on proximal 1/2–3/4 of each stem; blades of undivided cauline leaves ovate to orbiculate, margins entire or denticulate, seldom prickly, midribs rarely prickly-setose. |
Involucres | 12–15 mm. |
8–13+ mm. |
Florets | 10–15; corollas yellow, usually deliquescent. |
7–15(–30+); corollas yellow (sometimes streaked with violet), usually deliquescent. |
Phyllaries | usually reflexed in fruit. |
usually erect in fruit. |
Heads | in paniculiform arrays. |
usually in corymbiform, sometimes in paniculiform, arrays. |
Cypselae | bodies purplish to blackish, ± flattened, ± elliptic, 3.5–4 mm, beaks ± filiform, 2.5–3.5 mm, faces 5–7-nerved; pappi white, 5–6 mm. |
bodies pale grayish to whitish or tan, ± flattened, obovate, 3–4 mm, beaks ± filiform, 3–5 mm, faces 5–9-nerved; pappi white, 3.5–4+ mm. |
2n | = 18. |
= 18. |
Lactuca virosa |
Lactuca sativa |
|
Phenology | Flowering May, Oct. | Flowering mostly Jul–Sep. |
Habitat | Disturbed sites | Disturbed sites, abandoned plantings |
Elevation | 10–400 m [30–1300 ft] | 10–1000 m [30–3300 ft] |
Distribution |
AL; CA; DC; Europe [Introduced in North America]
|
AL; CA; CT; DC; DE; ID; IL; IN; MA; ME; MI; MO; NC; ND; NH; NJ; NM; NY; OH; OK; OR; PA; RI; VT; WA; WV; ON; Eurasia [Introduced in North America; introduced also in Mexico; introduced or ephemeral nearly worldwide]
|
Source | FNA vol. 19, p. 262. | FNA vol. 19, p. 263. |
Parent taxa | ||
Sibling taxa | ||
Name authority | Linnaeus: Sp. Pl. 2: 795. (1753) | Linnaeus: Sp. Pl. 2: 795. (1753) |
Web links |