Plantago L.
Annual or perennial herbs. Stems usually simple and very short, forming a caudex (rootstock) at or below ground level, sometimes elongated and branched, often with long hairs, occasionally woody and forming small subshrubs. Primary root persistent, or short-lived with subsequent adventitious root system. Lvs usually in basal rosettes, sometimes cauline, opposite or alternate. Fls in heads or cylindric spikes, rarely solitary, 4-merous, usually ⚥ and protogynous, sometimes unisexual; sepals similar to bracts, equal or not, free or connate at base. Corolla scarious or membranous; tube narrow, persisting at fr. apex; lobes usually patent or deflexed. Stamens epipetalous, usually exserted but included in cleistogamous fls. Ovary 2-locular, but sometimes appearing 4-locular by placental outgrowths; placentation axile. Ovules 1-6-(8) per loculus; style filiform. Capsule circumscissile, enclosed in persistent calyx. Seeds 1-many, ± mucilaginous when wet.
SYNOPSIS
The synopsis follows Pilger, R., in Engler, A., Das Pflanzenreich 269, Heft 102: 1-466 (1937).
- A. Subgen. PLANTAGO.
- Lvs alternate, usually in dense, radical rosettes. Ovules 2-many.
- 1. Sect. ARNOGLOSSUM.
- Plants generally large; taproot persistent. Lvs in rosettes. Spikes usually short, dense, many-flowered. Peduncle strongly ribbed. Ovules 2:
- 5. * lanceolata
- 2. Sect. CORONOPUS.
- Plants small to large; taproot persistent. Lvs in rosettes, often pinnate-dentate. Spikes short or long. Ovules 3-5:
- 3. * coronopus
- 3. Sect. LEUCOPSYLLIUM.
- Plants often small, branched, woody towards base; taproot persistent, often slender. Lvs radical but generally not in rosettes. Spikes usually short. Ovules 2:
- 1. * aristata
- 4. Sect. MESEMBRYNIA.
- Plants small to large, taprooted or shortly rhizomatous. Lvs in radical rosettes. Spikes various, often narrow. Ovules 5. Seeds 3-5, uppermost smaller, horizontal, and separated by placental outgrowth:
- 4. * debilis11. raoulii
- 5. Sect. MICROCALYX.
- Plants small; primary root short-lived. Lvs in dense rosettes. Fl. solitary on very short scape. Ovules 8-numerous:
- 10. obconica13. triandra
- 6. Sect. OLIGANTHOS.
- Plants small, often cushion-forming with multiple rosettes; primary root usually short-lived. Spikes very small, 1-few-flowered. Ovules 4-many:
- 9. lanigera12. spathulata14. triantha15. uniflora
- 7. Sect. PALAEOPSYLLIUM.
- Plants large with thick rhizome; primary root not persisting. Lvs in rosettes. Spikes elongate. Ovules 2-7:
- 8. aucklandica
- 8. Sect. PLANTAGO.
- Plants large or small; primary root not persisting. Lvs in rosettes. Spikes narrow, elongate. Corolla lobes small, ± reflexed. Ovules 6-many:
- 6. * major
- 9. Sect. VIRGINICA.
- Plants often large; primary root sometimes persisting. Lvs in rosettes. Spikes long. Fls closing at apex after anthesis. Ovules (2)-3:
- 2. * australis
- B. Subgen. PSYLLIUM.
- Lvs opposite, mainly cauline, not in dense rosettes. Ovules 2.
- 10. Sect. PSYLLIUM.
- Subshrubs:
- * afra7. * scabra
Key
c. 260 spp., temperate regions and montane tropics. Native spp. 8, naturalised 8.
Plantago spp. are notable for their plasticity in form and stature, and factors such as soil, light, precipitation and competition from other plants can profoundly affect these. Thus, not only can lf size and hairiness vary tremendously but also lf alignment varies from prostrate to erect in one population; in some indigenous spp. plants or even lvs on one plant may vary from entire to being furnished with long narrow teeth. Scape length, shape, and number of fls, are other characters that can exhibit great variation; short, fat and few-flowered spikes on short scapes or elongated, slender and many-flowered spikes on long scapes, can occur in a single sp. and are probably correlated with different environments. In a few indigenous spp. which have 1 or few fls, the variation in scape elongation after anthesis results in a range of plants from those with almost sessile capsules through to others which have capsules held high above the lvs.
