Sp. Pl. 2: 881. 1753. 1753
Gen. Pl. ed. 5, 375. 1754. 1754
Perennials [annuals], 20–200 cm. Leaves basal (usually withering before flowering) and cauline; petiolate (proximal) or sessile (distal); blade margins usually serrate to dentate, sometimes entire. Heads radiate [disciform, discoid], borne singly or in open, corymbiform arrays. Involucres hemispheric or campanulate, [5–]10–40 mm diam. Phyllaries persistent, in 4–7+ series. Receptacles flat or convex, smooth or alveolate, epaleate. Ray florets (15–)50–150+, pistillate, fertile; corollas yellow [orange], laminae 10–30+ mm. Disc florets mostly (50–)100–250+; corollas yellow, lobes 5. Cypselae ± columnar (subterete) or prismatic (± 4–5-ribbed or -angled); pappi persistent, of basally connate, barbellate bristles or setiform scales in 1 series. x = 8, 9, 10.
Introduced; Old World.
Species ca. 100 (3 in the flora).
The three species in the flora are probably escapes from cultivation. Formerly, Inula was circumscribed more broadly.
|1||Blades of basal (and proximal cauline) leaves 100–200 mm wide; involucres (20–)30–40 mm diam.; outer phyllaries 6–8(–20+) mm wide||Inula helenium|
|1||Blades of basal (and proximal cauline) leaves mostly 10–30 mm wide; involucres 7–15(–20) mm diam.; outer phyllaries mostly 0.5–2.5 mm wide||> 2|
|2||Blades of cauline leaves lance-elliptic to lance-linear (venation not raised adaxially, reticulation not evident); outer phyllaries 4–6 × 0.5–0.8 mm||Inula britannica|
|2||Blades of cauline leaves broadly elliptic to lanceolate (venation raised adaxially, reticulation prominent); outer phyllaries 5–7 × 1.5–2.5 mm||Inula salicina|