;"O. bartlingii";"O. ingens";"O. owerinii";"O. laxissima";"O. minor" Inflorescence;"cylindrical to ovate, ± dense, usually shorter than the rest of the stem";"usually long, rarely short (small specimens), cylindrical, somewhat lax, usually many-flowered";"usually short-cylindrical to ovate, ± lax, usually few-flowered";"usually long, or less frequently short (small specimens), cylindrical, very lax, usually many-flowered";"usually long, rarely short (small specimens), cylindrical, dense at the first of anthesis, becoming lax later, usually many-flowered (except small specimens)" "Floral bract";"about two thirds of the length of the corolla";"as long as the corolla tube, slightly shorter than the corolla";"as long as the corolla or slightly shorter or longer than the corolla";"as long as the corolla tube, slightly shorter than the corolla";"as long as the corolla" "Calyx segments";"bidentate, teeth short, usually subulate at tip";"deeply bidentate, teeth frequently filiform";"segments entire or less frequently bidentate, narrowly subulate";"usually entire or less frequently bidentate, rarely with 4 teeth, teeth narrowly subulate to filiform";"bidentate or less frequently entire, teeth subulate to narrowly subulate but not filiform" "Corolla, length";"12‒18 mm";"(20–) 23–24 (–30) mm";"15–20 (‒30) mm";"(20) 22–24 (–25) mm";"10–19 mm" "Corolla, form";tubular;campanulate;campanulate-infundibuliform;tubular-infudibuliform;tubular "Corolla, dorsal line";"evenly curved at the proximal and distal part, almost straight at the middle";"almost straight, except evenly curved at the proximal part";"almost straight, except evenly curved at the proximal part and, sometimes, slightly bent forward at the distal part";"almost straight, except evenly curved at the proximal part and, sometimes, slightly bent forward at the distal part";"evenly curved at the proximal part, almost straight at the middle and slightly bent forward at the distal part" "Corolla, colour";"yellow, brownish-yellow, pinkish ± tinged with purple";"yellow, rarely violet, dark pink";"pale violet to purple, rarely cream";"purple, dark or light pink, rarely dirty yellow, light brown, sometimes with ± dark purplish veins";"whitish or yellowish-white, more or less coloured purple, with dark purplish veins, rarely entirely yellow" Filaments;"inserted 1–3 mm above the corolla base; with long hairs at the basal half and sparsely glandular pubescent under the anthers";"inserted 1 (–2) mm above the corolla base; with long hairs at the basal half and sparsely glandular pubescent (almost glabrous) under the anther";"inserted 3–4 mm above the corolla base; hairy at the basal half (or third) and sparsely glandular pubescent under the anthers";"inserted (2–)3–5 mm above the corolla base; hairy at the base and sparsely glandular pubescent under the anthers";"inserted 2–3 (–5) mm above the corolla base, glabrous or sparsely hairy at the base and sparsely glandular pubescent under the anthers" Stigma;yellow;"mainly yellow or orange, rarely reddish, violet, dark pink";"reddish to deep purple";"dark pink, purple, violet, rarely orange, pale to dark yellow";"pinkish, ± deep purple, rarely yellow or whitish" Host;"Apiaceae (Seseli)";"Apiaceae (Heracleum)";"Fabaceae (Trifolium and Vicia) and rarely Asteraceae (Leontodon and Lactuca)";"trees and shrubs, Betulaceae, Oleaceae, Fagaceae, Sapindaceae, Cornaceae, Lythraceae, Fabaceae, Anacardiaceae (e.g., Fraxinus, Fagus, Carpinus, Rhus)";"Fabaceae, Asteraceae, Apiaceae, etc. (e.g., Trifolium, Medicago, Hypochaeris, Leontodon, Chondrilla, Daucus)"