Nabalus crepidineus Michx.

Tall White Lettuce

Nabalus crepidineus plant

Family - Asteraceae

Stems - Relatively stout, glabrous to moderately pubescent, often with purple mottling.

Nabalus crepidineus stemStem.

Leaves - With winged petioles, broadly ovate, usually coarsely and irregularly toothed, roughened or inconspicuously pubescent.

Nabalus crepidineus leavesUpper stem leaf.

Nabalus crepidineus leavesLower stem leaf.

Inflorescence - Broad, elongate panicles, terminal and often from upper leaf axils, heads nodding.

Nabalus crepidineus inflorescenceInflorescence.

Involucre - Green, 12-16 mm long, with 10-15 narrowly oblong inner bracts, pubescent with stout hairs.

Nabalus crepidineus involucreInvolucre.

Flowers - Ligulate florets 15-30, cream to light yellow; stamenal tubes and styles conspicuously exserted at anthesis.

Nabalus crepidineus flowerFlower.

Fruits - 5-6 mm long, yellowish to reddish brown, terete, beakless.

Nabalus crepidineus fruitsFruits.

Flowering - August-October.

Habitat - Bottomland forests, banks of streams, moist depressions.

Origin - Native to U.S.

Other info. - This striking plant is known from a handful of Missouri counties, mostly toward the eastern side of the state. It is often overlooked because it does not reliably bolt and bloom. Basal leaves, arrowhead shaped with conspicuously winged petioles, can be found in bottomland forests in the springtime, but most of these die back by midsummer without sending up flowering stems. However, populations which are found in flowering condition will often flower reliably year after year.
This plant was long known as Prenanthes crepidinea. Prenanthes is an Old World genus, and the related North American species have been moved to the genus Nabalus.

Photographs taken near Dutzow, Warren County, MO, 9-16-2011, 10-2-2011, 9-20-2015, 9-3-2016, 10-5-2016, and 9-29-2017 (SRTurner).