Steirodiscus tagetes (L.) Schltr.

Annual herb, (50-)100-200 mm, stem flexuous, corymbosely branched above. Leaves alternate, ascending, mostly 30-60 x 15-20 mm, pinnatisect or some leaves rarely bipinnatisect, with up to 8 lobes on each side, lobes alternate or subopposite and subsecund, filiform to oblong, 5-12 x 0.5-1.0(-1.5) mm, entire or with 1 or 2 lobules, uppermost leaves sometimes simple and linear-filiform. Capitula solitary, pedunculate; peduncles 10-60 mm long, with 2 or 3 minute, scale-like bracts. Involucre campanulate, 5-8 x 4-5(-6) mm, bracts (8-)10-13(-15), connate for two-thirds their length, free parts lanceolate, with narrow membranous margins, penicillate. Ray florets as many as bracts and opposite them, 8-15, yellow or rarely pale orange; tube narrowly cylindrical, ±3.5 mm long, with abaxial trichomes in transverse band at top of tube, trichomes fleshy and coalescent or palmate and forming distinct fimbriate collar at junction between tube and blade; blade 8-10 x 3-4 mm, spreading, recurved apically; ovary terete, 2.5 mm long, glabrous, longitudinally colliculate, style branches partly or fully exserted, ±1 mm long. Disc florets bisexual, yellow, 6-7 mm long; tube narrowly funnel-shaped, ±4.5 mm long, sparsely pubescent in distal half; lobes ±1 mm long, ovate, acute; ovary terete, 2 mm long, glabrous, longitudinally colliculate, style branches ±1 mm long. Cypselas obovoid-prismatic, ±2.5 mm long, glabrous, longitudinally colliculate, obscurely 5-angled and 10-ribbed.