Plantago

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

Bassett, I. J. 1966. Taxonomy of North American Plantago L. section Micropsyllium Decne. Canad. J. Bot. 44: 467–479.

Bassett, I. J. 1967. Taxonomy of Plantago L. in North America: Sections Holopsyllium Pilger, Palaeopsyllium Pilger, and Lamprosantha Decne. Canad. J. Bot. 45: 565–577.

Bassett, I. J. 1973. The Plantains of Canada. Ottawa.

Kuiper, P. J. C. and M. Bos, eds. 1992. Plantago: A Multidisciplinary Study. Berlin.

Rahn, K. 1974. Plantago section Virginica: A taxonomic revision of a group of American plantains using experimental, taximetric and classical methods. Dansk Bot. Ark. 30: 1–180.

Rahn, K. 1978. Plantago ser. Gnaphaloides Rahn: A taxonomic revision. Bot. Tidsskr. 73: 137–154.

Rahn, K. 1979. Plantago ser. Ovatae. A taxonomic revision. Bot. Tidsskr. 74: 13–20.

Ronsted, N. et al. 2002. Phylogenetic relationships within Plantago (Plantaginaceae): Evidence from nuclear ribosomal ITS and plastid trnL-F sequence data. Bot. J. Linn. Soc. 139: 323–338.

Lower Taxa

Plantago afra, Plantago argyrea, Plantago aristata, Plantago australis, Plantago canescens, Plantago cordata, Plantago coronopus, Plantago elongata, Plantago erecta, Plantago eriopoda, Plantago firma, Plantago floccosa, Plantago helleri, Plantago heterophylla, Plantago hookeriana, Plantago indica, Plantago lanceolata, Plantago macrocarpa, Plantago major, Plantago maritima, Plantago media, Plantago ovata, Plantago patagonica, Plantago pusilla, Plantago rhodosperma, Plantago rugelii, Plantago sempervirens, Plantago sparsiflora, Plantago subnuda, Plantago tweedyi, Plantago virginica, Plantago wrightiana

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