This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Plantago pusilla Nutt. Gen. 1: 100. 1818.
Annual, puberulent; scapes filiform, 2-7' high, longer than the linear-filiform, mostly entire, blunt-pointed obscurely 1-nerved leaves. Leaves about ¥' wide; spikes slender, linear, rather loosely flowered, 1/2'-3' long, 1 1/2"-2" thick; flowers imperfectly dioecious or polygamous; sepals oblong, obtuse, about as long as the bract, scarious-margined; corolla-lobes of the more fertile plants becoming erect over the pyxis; stamens 2; pyxis ovoid-oblong, obtuse, one-fourth to one-third longer than the calyx, about 4-seeded, cir-cumscissile at about the middle; seeds nearly flat on both sides.
In dry sandy soil, Massachusetts to Georgia, Illinois, Kansas and Texas. April-Aug.
Plantago heterophylla Nutt. Trans. Am. Phil. Soc. (II.) 5: 177. 1833-37- Annual, similar to the preceding species, but glabrous or slightly puberulent; scapes ascending or spreading, equalling or exceeding the leaves, 2'-10' long. Leaves narrowly linear or filiform, the larger about 2" wide, entire or often with several distant small teeth or linear lobes; spikes loose, linear, 1/2'-5' long; sepals oblong, obtuse, scarious-margined, mostly shorter than the bract; corolla-lobes in the more fertile plants becoming erect over the pyxis; stamens 2; pyxis oblong, subacute, about twice as long as the calyx, 7-30-seeded, circumscissile rather below the middle; seeds somewhat angled, scarcely concave on the face.
In moist soil, New Jersey to Florida, Illinois, Arkansas, Texas and apparently introduced in California. April-July.
Plantago arenaria W. & K. Pl. Rar. Hung. 1: 51. pl. 51. 1802.
Annual, pubescent, somewhat viscid; stem simple, or commonly becoming much branched, leafy, 3'-15' high. Leaves opposite, or whorled, narrowly linear, entire, sessile, 1'-3' long, about 1" wide; peduncles axillary, often umbellate at the ends of the stem and branches, slender, as long as the leaves or longer; heads of flowers conic, oval, or subglobose, 5"-10" long, about 5" thick; lower bracts acute or acuminate; calyx-lobes unequal; corolla-lobes ovate to lanceolate, acute; capsule 2-seeded.
Fields, Dayton, Ohio, and Lancaster County, Pennsylvania. Adventive from central Europe. Summer.