Cephalaria sect. Atrocephalae, Szabo, 1940

Ranjbar, Massoud & Ranjbar, Zahra, 2017, A taxonomic revision of Cephalaria subgen. Cephalaria sect. Atrocephalae (Caprifoliaceae) from Iran, Phytotaxa 311 (2), pp. 101-138 : 102-103

Key to the species of Cephalaria sect. Atrocephalae in Iran

1. Plants up to 40 cm, stems sparsely pilose in the lower part ....................................................................................... C. sparsipilosa

– Plants up to 150 cm, stems glabrous or completely hairy.................................................................................................................2

2. Plants up to 150 cm, leaves up to 40 cm, capitula up to 4 cm in diameter (except for C. kleinii ).....................................................3

– Plants up to 120 cm, leaves shorter than 20 cm, capitula 1.5–2.5 cm in diameter............................................................................ 6

3. Stem pubescent, not distinctly striate; leaves up to 20 cm long, ovate-lanceolate, dark green; capitula up to 3 cm long; involucral bracts densely sericeous or lanate, receptacular bracts hirsute, apex black-speckled ...................................................................... 4

– Stem glabrous, striate; leaves up to 40 cm long, elliptic to ovate, light green; capitula up to 4 cm long; both involucral and receptacular bracts pilose and pubescent....................................................................................................................................................5

4. Stem loosely covered with pubescent hairs in upper part (hairs up to 1 mm long), abaxial leaves green-brownish, basal leaves undivided, segments of cauline leaves acute...................................................................................................................... C. kotschyi

– Stem sparsely covered with pubescent hairs (less than 1 mm long), abaxial leaves greyish, basal leaves pinnatipartite, segments of cauline leaves moderately acuminate ................................................................................................................................... C. kleinii

5. Cauline leaves villous, with ca. 6 segments; peduncle up to 15 cm long; receptacular bracts in 5 series ......................... C. procera

– Cauline leaves glabrous, with 8–12 segments; peduncle up to 35 cm long; receptacular bracts in 7–9 series....... C. chaldoranensis

6. Stem subglabrous, plant looks leafless, leaves minute, angustate, less than 1 cm wide; lower and median cauline leaves lanceolate to linear, with up to 6 pairs of lateral segments; capitula 0.8–1.2 cm in diameter, few-flowered; both involucral and receptacular bracts pinkish ...................................................................................................................................................................... C. juncea

– Stem pilose-pubescent or puberulent, plant leafy; leaves more than 1 cm wide, lower and cauline leaves oblong-elliptic or oblong-lanceolate, undivided or with up to 3 pairs of lateral segments; capitula up to 2 cm in diameter, many-flowered; involucral and receptacular bracts brown to straw-coloured at base, often blackish at apex.....................................................................................7

7. Stem pilose, leaves hirsute or hispid often on abaxial surface..........................................................................................................8

– Stem pubescent or puberulent, leaves pubescent or pilose on both surfaces....................................................................................9

8. Plant ascending, few-stemmed; indumentum straw-yellow; upper leaves simple ............................................................... C. hirsuta

– Plant diffuse, many-stemmed; indumentum white; upper leaves pinnatisect .............................................................. C. qeydarensis

9. Stem divided, branches arising from a single stem; basal leaves often lyrate to pinnatisect...........................................................10

– Stem simple or with few branches; basal leaves simple..................................................................................................................11

10. Involucral and receptacular bracts purple-blackish at apex ................................................................................ C. torbatejamensis

– Involucral and receptacular bracts straw-coloured.................................................................................................... C. microcephala

11. Stems up to 40 cm; peduncle up to 12 cm long, basal leaves often densely foliate in vagina........................................................12

– Stems up to 90 cm; peduncle up to 55 cm long, basal leaves loosely foliate in vagina..................................................................13

12. Leaves green to brownish-green when dried, surface rather glabrous or with sparse hairs only along the midvein and margins, number of basal leaves up to 50; capitula heterocephaloid, 1–3 on the peduncle ............................................................. C. axillaris

– Leaves greyish-green when dried, pilose on both surfaces, number of basal leaves up to 10; capitula homocephaloid, single on the peduncle ........................................................................................................................................................................ C. golestanica

13. Stems undivided; basal leaves entire or slightly serrate (up to 5 teeth)..........................................................................................14

– Stems slightly branched; basal leaves serrate (up to 50 teeth)........................................................................................................15

14. Basal leaves petiolate (ca. 2 cm long), leaves serrate, peduncle up to 55 cm long, receptacular bracts straw-coloured at base of dorsal surface, blackish at apex .................................................................................................................................. C. bojnordensis

– Basal leaves non-petiolate, leaves entire, peduncle up to 18 cm long, receptacular bracts straw-coloured with purple nerves ......... ..................................................................................................................................................................................... C. integerrima

15. Upper leaves divided (2–6 segments), receptacular bracts up to 10 mm long, straw-brownish at base and blackish at apex ............ ........................................................................................................................................................................................ C. sublanata

– Upper leaves undivided; receptacular bracts 5–6 mm long, straw-coloured with brown nerves ................................. C. subindivisa