Plantago
Sp. Pl. 1: 112. 1753.
Herbs, annual or perennial, sometimes biennial [rarely suffrutescent or arborescent]; caudex usually present when perennial. Stems present or absent, if present, erect, glabrous or hairy. Leaves usually basal, usually alternate, (cauline and opposite in P. afra, P. indica, P. sempervirens); petiole absent or present; blade fleshy, leathery or not, margins entire or toothed. Scapes erect or ascending, rarely decumbent (P. coronopus), surpassing leaves, sometimes slightly so (P. tweedyi) or not (P. major). Inflorescences axillary, spikes or spiciform, dull, sometimes shiny (P. canescens, P. lanceolata, P. media); bracts present. Pedicels absent or present; bracteoles absent. Flowers bisexual; sepals 3 or 4, nearly distinct (abaxials connate in P. lanceolata), oblong, calyx radially, rarely bilaterally, symmetric, cuplike; corolla semitransparent, radially or weakly bilaterally symmetric, lateral lobes smaller, ± tubular to ± funnelform, tube base not spurred or gibbous, tube glabrous, rarely hairy (P. coronopus, P. maritima), lobes 4; stamens 2 or 4, free, equal, filaments glabrous; staminode 0; ovary 2-locular, placentation free-central, sometimes axile; stigma elongate. Fruits pyxides, lanceoloid, rarely ovoid (P. macrocarpa), dehiscence circumscissile (indehiscent or dehiscence not circumscissile in P. macrocarpa). Seeds (1 or) 2–35, black or brown, sometimes dark red (P. rhodosperma) or yellowish-brown (P. virginica), oblong, wings absent. × = 4, 5, 6.
Distribution
North America, Mexico, Central America, South America, Europe, Asia, Africa, Pacific Islands (New Zealand), Australia
Discussion
Species ca. 210 (32 in the flora).
Plantago lanceolata and P. major have become established on all continents except Antarctica. A specimen of P. asiatica Linnaeus (New York City, US 295731) is ambiguous as to locality, and there is no evidence that it is established outside of cultivation in the flora area. Among North American Plantago, several native species have been introduced to states or provinces outside their native range.
For species with bilaterally symmetric calyces, sepal lengths in the descriptions are for the adaxial sepals.
Selected References
Lower Taxa
Key
| 1 | Leaves cauline. | > 2 |
| 2 | Perennials, sometimes woody. | Plantago sempervirens |
| 2 | Annuals. | > 3 |
| 3 | Spikes glandular-hairy; all bracts similar. | Plantago afra |
| 3 | Spikes eglandular; proximal bracts strongly differing from distal bracts. | Plantago indica |
| 1 | Leaves basal. | > 4 |
| 4 | Leaf margins usually 1- or 2-pinnatifid; scapes decumbent, sometimes erect; corolla tubes hairy. | Plantago coronopus |
| 4 | Leaf margins entire, toothed, or lobed; scapes erect or ascending; corolla tubes glabrous, rarely hairy (P. maritima). | > 5 |
| 5 | Annuals; leaf blades linear, narrowly lanceolate, narrowly elliptic, or almost filiform; roots taproots. | > 6 |
| 6 | Seeds (3 or)4–25(–30); corollas radially symmetric, lobes 0.5–1 mm; leaf blade surfaces glabrous or hairy. | > 7 |
| 7 | Seeds 10–25(–30), 0.5–0.8 mm. | Plantago heterophylla |
| 7 | Seeds (3 or)4–9(–12), 0.8–2.5 mm. | > 8 |
| 8 | Corolla lobes spreading or reflexed, not forming a beak; seeds (3 or)4–9(–12), 1.5–2.5 mm. | Plantago elongata |
| 8 | Corolla lobes erect, forming a beak; seeds 4, 0.8–1.3 mm. | Plantago pusilla |
| 6 | Seeds 2; corollas bilaterally or radially symmetric, lobes 1.3–3.6 mm; leaf blade surfaces lanate, sericeous, or villous, rarely glabrate or glabrous. | > 9 |
| 9 | Spikes: flowers in spirals; scapes without antrorse hairs; bracts ovate or elliptic. | Plantago ovata |
| 9 | Spikes: flowers in whorls or pairs; scapes with some antrorse hairs; bracts ovate, triangular, or almost linear. | > 10 |
| 10 | Corollas radially symmetric, lobe bases obtuse or slightly cordate. | > 11 |
| 11 | Scapes with antrorse, long and short hairs; bract lengths 0.3–0.8 times sepals; corolla lobes 2–2.7 mm; California, Oregon. | Plantago erecta |
| 11 | Scapes with patent, long and antrorse, short hairs; bract lengths 0.6–2.2 times sepals; corolla lobes 3–3.6 mm; New Mexico, Texas. | Plantago helleri |
| 10 | Corollas bilaterally symmetric, lobe bases slightly to deeply cordate. | > 12 |
| 12 | Leaf blades: adaxial surfaces glabrous or sparsely villous, margins entire, rarely toothed; stems 10–40 mm. | > 13 |
| 13 | Bract lengths 2–12 times sepals; corolla lobes: adaxials 1.4–2.3 mm, laterals symmetric; flowering spring–fall. | Plantago aristata |
| 13 | Bract lengths 0.4–0.8 times sepals; corolla lobes: adaxials 2.4–3 mm, laterals asymmetric; flowering summer. | Plantago wrightiana |
| 12 | Leaf blades: adaxial surfaces sericeous or villous, rarely lanate, margins entire or toothed; stems 0–20 mm. | > 14 |
| 14 | Bracts ovate, lengths 0.4–0.7 times sepals; leaves 1.5–4 mm wide; anther connectives slightly elongated, apices obtuse. | Plantago argyrea |
| 14 | Bracts triangular or ovate, lengths 0.6–2 times sepals; leaves 1–4 or 4–10 mm wide; anther connectives elongated to significantly elongated, apices acute. | > 15 |
| 15 | Bract lengths 0.6–1.4 times sepals; corolla lobes 2.2–2.5 mm; leaves 4–10 mm wide, blade margins toothed, rarely entire; flowering spring. | Plantago hookeriana |
| 15 | Bract lengths 1–2 times sepals; corolla lobes 1.6–2.1 mm; leaves 1–4 mm wide, blade margins entire, rarely toothed; flowering early summer. | Plantago patagonica |
| 5 | Perennials or annuals; leaf blades ovate, elliptic, or lanceolate, sometimes cordate-ovate, lanceolate-spatulate, linear, oblanceolate, obovate, or oval; roots taproots or fibrous. | > 16 |
| 16 | Corolla lobes usually forming a beak, erect or patent; annuals or perennials (usually without caudex). | > 17 |
| 17 | Annuals; roots taproots. | > 18 |
| 18 | Seeds: adaxial faces flat; bracts triangular, 2–3.1 mm; sepals 1.8–2.8 mm. | Plantago firma |
| 18 | Seeds: adaxial faces concave; bracts ovate or triangular, 1.6–3.2 mm; sepals 1.5–3.6 mm. | > 19 |
| 19 | Sepals 2.7–3.6 mm, apices acuminate; bracts 2.5–3.2 mm, narrowly triangular or triangular; seeds dark red. | Plantago rhodosperma |
| 19 | Sepals 1.5–2.4 mm, apices obtuse; bracts 1.6–2.4 mm, narrowly ovate or ovate; seeds brown or yellowish brown. | Plantago virginica |
| 17 | Perennials; roots taproots or fibrous. | > 20 |
| 20 | Adaxial surfaces of leaves: hairs floccose, slender, 4–6 × 0.01–0.03 mm. | Plantago floccosa |
| 20 | Adaxial surfaces of leaves: hairs not floccose, less than 2 mm long, more than 0.03+ mm wide. | > 21 |
| 21 | Roots fibrous; sepals 2–2.5 mm. | Plantago australis |
| 21 | Roots taproots; sepals 2.6–3.1 mm. | Plantago subnuda |
| 16 | Corolla lobes not forming a beak, spreading or reflexed; perennials (sometimes with caudex), rarely annuals. | > 22 |
| 22 | Fruits ovoid, indehiscent or dehiscence not circumscissile. | Plantago macrocarpa |
| 22 | Fruits lanceoloid, dehiscence circumscissile. | > 23 |
| 23 | Leaf blades linear to lanceolate, veins not conspicuous; corolla tubes hairy. | Plantago maritima |
| 23 | Leaf blades lanceolate, linear, oblanceolate, oval, cordate-ovate, lanceolate-spatulate, ovate, or elliptic, veins conspicuous; corolla tubes glabrous. | > 24 |
| 24 | Spikes grayish, whitish, or yellowish, shiny, corolla lobes of neighboring flowers often overlapping. | > 25 |
| 25 | Sepals: adaxial 2 connate; scapes groove-angled. | Plantago lanceolata |
| 25 | Sepals: adaxial 2 nearly distinct; scapes not groove-angled. | > 26 |
| 26 | Leaves ascending, 6–20 mm wide, blades linear to lanceolate or oblanceolate, surfaces hairy (hairs 1 mm) or glabrate; seeds 3–7, 1–1.8 mm. | Plantago canescens |
| 26 | Leaves prostrate, sometimes ascending, 30–70 mm wide, blades elliptic to ovate, surfaces hairy (hairs 0.5 mm); seeds 2–4, 2 mm. | Plantago media |
| 24 | Spikes brownish or greenish, dull, corolla lobes of neighboring flowers not overlapping. | > 27 |
| 27 | Caudices absent. | > 28 |
| 28 | Fruits (2–)4–5 mm, dehiscing at middle; seeds 5–35, 0.5–1 mm; bracts 0.5–1 mm. | Plantago major |
| 28 | Fruits 4–6(–8) mm, dehiscing proximal to middle; seeds 4 or 5(–8), 1.5–2 mm; bracts 2 mm. | Plantago rugelii |
| 27 | Caudices well developed, conspicuous. | > 29 |
| 29 | Spikes densely flowered, rachises not clearly visible between flowers; scapes slightly surpassing leaves. | Plantago tweedyi |
| 29 | Spikes loosely flowered, rachises visible between flowers; scapes surpassing leaves. | > 30 |
| 30 | Leaf blades: lateral veins branching from midvein distal to base. | Plantago cordata |
| 30 | Leaf blades: lateral veins branching from base. | > 31 |
| 31 | Caudices brown-woolly; c, w United States and Canada. | Plantago eriopoda |
| 31 | Caudices glabrous; se United States. | Plantago sparsiflora |