Annual herb with long, fleshy roots flowering stem to 30 cm tall Leaves: basal, long-stalked, 12 - 25 cm long, 8 - 20 cm wide, egg- to heart-shaped, fleshy, with lateral veins arising from the midvein. Inflorescence: a thin, loose spike of many flowers, arising from a leafless stalk (scape), to 30 cm long, about 1 cm wide, interrupted and exposing axis. Flowers: stalkless or nearly stalkless, whitish, tiny, under 1 mm wide, subtended by round to egg-shaped bracts. Stamens four, exserted, alternate with corolla lobes. Style one. Sepals: four, green, 3 - 3.5 mm long, about as long as bracts, broadly rounded to egg-shaped with a rounded or blunt tip, nearly flat, narrowly scarious-margined (dry, thin, and membranous), with a narrow keel. Fruit: a dehiscent capsule (circumscissile), 0.5 - 1 cm long, egg-shaped. Seeds two to four, dark brown, 3 - 4 mm long, moist and slimy. Corolla: four-lobed, whitish, under 1 mm wide, scarious (dry, thin, membranous).
Similar species: This species is easily distinguished from other Plantago by its hollow scapes and heart-shaped leaves with lateral veins that arise from the midvein.
Flowering: mid-April to mid-May
Habitat and ecology: Rare in the Chicago Region, usually found growing in shaded areas along or in clear, cool, gravel-bottom streams. It has a preference for calcareous habitats.
Occurence in the Chicago region: native
Etymology: Plantago comes from the Latin word planta, meaning footprint. Cordata means heart-shaped, referring to the leaves.
Glabrous perennial with several long, fleshy roots 0.5-1.3 cm thick; principal lvs cordate-ovate, mostly 12-25 נ8-20 cm, the main lateral veins not parallel to the margin, tending to arise from the proximal part of the midvein within the blade, scapes to 3 dm, stout and hollow; spikes to 3 dm, interrupted, the axis exposed; bracts and sep about equal, broadly round-ovate, nearly flat, with very narrow keel, herbaceous sides, and narrow scarious margins, obtuse or rounded at the tip; fr ovoid, 5-10 mm, circumscissile at or just below the middle; seeds 2(-4), 3-4 mm, smooth, mucilaginous; 2n=24. Semiaquatic, in marshes and along streams, especially on calcareous substrate; O. and s. Ont. to Wis. and Mo., and occasionally to N.Y., Va., N.C., Ga. and Ala.; now rare. Mainly spring.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Reported from Kosciusko County and from the Lower Wabash Valley. It is extremely rare. I have found it in a small open ditch in Wells County, in a low woods in Knox County which was inundated much of the time, and in an open ditch in a woods in the southeast corner of Whitley County.