Arnoglossum plantagineum Raf.

Indian Plantain

Arnoglossum plantagineum plant

Family - Asteraceae

Habit - Perennial forb, on tuberous-thickened rootstock.

Stems - Erect, to 1.6 m, glabrous, not glaucous, usually unbranched below the inflorescence, usually with deep reddish stripes, especially near the base.

Arnoglossum plantagineum stemStem.

Leaves - Basal and alternate, simple, thickened and leathery in texture, glabrous, not glaucous. Basal and lower leaves long-petiolate, the petioles to 10 cm, the blades 8-20 cm long, elliptic to ovate, unlobed, the tip rounded to bluntly pointed, tapered at the base, the margins entire or occasionally shallowly toothed, the venation parallel with 7-10 main veins diverging from the base and converging toward the tip, the main veins strongly expressed abaxially. Upper leaves reduced, entire, tapered at the base.

Arnoglossum plantagineum basalsBasal leaves.

Arnoglossum plantagineum leavesBasal leaves.

Arnoglossum plantagineum leaf1Stem leaf.

Arnoglossum plantagineum leaf2Stem leaf, abaxial.

Inflorescence - Terminal and axillary panicles, usually flat-topped, the peduncles whitish, glabrous. Leaflike bracts in inflorescence.

Arnoglossum plantagineum inflorescenceInflorescence.

Heads - Involucre 7-10 mm long, the inner bracts with a sharp, dorsal keel, green, usually with a white dorsal band and tip, the outer series of a few minute, ascending and incurved bracts toward the tip of the stalk of the head. Heads typically with 5 disk florets.

Ray flowers - Absent.

Disk flowers - Corollas 5-lobed, 8-11 mm long, glabrous, white or cream-colored. Lobes to 3 mm long, often recurved or curling. Stamens 5, exserted. Anthers orange to brown, 2.7 mm long, connate around style. Style glabrous, bifurcate. Pappus of capillary bristles to 8 mm long.

Arnoglossum plantagineum headsHeads.

Arnoglossum plantagineum flowersFlorets.

Arnoglossum plantagineum disk flowerIndividual disk floret with pappus.

Flowering - May - August.

Fruits - Achenes to 5 mm long, brown, 10-ribbed, beakless, with spreading pappus.

Arnoglossum plantagineum flowersMature fruits

Habitat - Prairies, wet meadows, glades, rocky open woods, thickets, roadsides, railroads.

Origin - Native to U.S.

Other info. - This plant is always a treat to find. It occurs in scattered locations throughout most of Missouri, and across much of the U.S. Midwest and southern states. It is an easy ID, with distinctly leathery leaves, a stem which usually is red-striped, and shining white inflorescences. The leaf shape and texture serve to differentiate it from Missouri's other Indian plantains. This striking species is deserving of more widespread cultivation. It can apparently tolerate a wide range of moisture regimens. If you wish to replant a real prairie habitat, you must include this plant.

The North American Indian plantains were formerly placed in the genus Cacalia, and a synonym formerly used for this plant was Cacalia plantaginea (Raf.) Shinners.

Photographs taken off Hwy NN, Shannon County, MO., 6-17-03, and off Hwy H, Shannon County, MO., 6-13-05 (DETenaglia); also at Shaw Nature Reserve, Franklin County, MO, 6-15-2007, and Onondaga Cave State Park, 6-18-2014 and 7-31-2014 (SRTurner).