Plantago australis

Perennials; caudex glabrous; roots fibrous, stout. Stems 0–10 mm. Leaves 40–350 × 6–77 mm; blade elliptic to narrowly elliptic, margins entire, veins conspicuous, surfaces pilose, rarely glabrate, adaxial surface hairs not floccose, less than 2 mm long, more than 0.03 mm wide. Scapes 30–560 mm, hairy, hairs antrorse, short. Spikes greenish or brownish, 100–1000 mm, densely flowered; bracts narrowly triangular, 1.6–4.2 mm, length 0.8–1.5 times sepals. Flowers: sepals 2–2.5 mm; corolla radially symmetric, lobes erect, forming a beak, 2–2.8 mm, base obtuse; stamens 4. Seeds 3, 1.2–2.2 mm. 2n = 24.

Phenology: Flowering summer.
Habitat: Open places.
Elevation: 0–1000 m.

Ariz., Mexico, Central America, South America

Discussion

Plantago australis occurs in Cochise, Coconino, and Pima counties. Plantago australis is most diverse in South America, where as many as 16 subspecies (K. Rahn 1974) may be recognized. Plants from California identified as P. hirtella are most likely P. subnuda. However, since the most important distinguishing character of P. australis is the absence of the developed taproot (which is fragile and often broken in herbarium specimens), all these samples require careful examination. Further research is needed also to clarify the circumscriptions of P. australis and P. subnuda.

Selected References

None.

Lower Taxa