116c. Leaves tapering to a short petiole; principal leaves whorled =Rosin Weed, Silphium trifoliatum.= 116d. Leaves abruptly rounded at the sessile base, all opposite (Ox-eye) --117. 117a. Leaves smooth =Ox-eye, Heliopsis helianthoides.= 117b. Leaves rough =Ox-eye, Heliopsis scabra.= 118a. Principal stem-leaves lobed or divided --119. 118b. Principal stem-leaves entire or serrate --127. 119a. Submerged aquatic; leaf-segments filiform =Water Marigold, Bidens beckii.= 119b. Terrestrial plants; leaves merely 3-lobed (3-8 dm. high; late spring and summer) (Tickseed) --120. 119c. Terrestrial plants; leaves compound or dissected (summer and autumn) --121. 120a. Leaf-lobes linear-oblong, all about equal =Tickseed, Coreopsis palmata.= 120b. Lateral leaf-lobes very much smaller than the terminal =Tickseed, Coreopsis lanceolata.= 121a. Leaf-segments entire (Tickseed) --122. 121b. Leaf-segments serrate (5-15 dm. high) (Tickseed Sunflower) --124. 122a. Leaf-segments numerous, linear or nearly so (4-10 dm. high) --123. 122b. Leaf-segments 3-5, lanceolate (1-3 m. high) =Tickseed, Coreopsis tripteris.= 123a. Rays yellow throughout =Tickseed, Coreopsis verticillata.= 123b. Rays brown, at least at the base =Tickseed, Coreopsis tinctoria.= 124a. Achenes wedge-shape, the inner ones less than 2 mm. wide --125. 124b. Achenes obovate, the inner ones more than 2 mm. wide =Tickseed Sunflower, Bidens aristosa.= 125a. Leaf-lobes lanceolate =Tickseed Sunflower, Bidens trichosperma.= 125b. Leaf-lobes linear =Tickseed Sunflower, Bidens trichosperma var. tenuiloba.= 126a. Outer leaf-like bracts 10-16; achenes brown =Beggar Ticks, Bidens vulgata.= 126b. Outer leaf-like bracts 5-8; achenes black =Beggar Ticks, Bidens frondosa.= 126c. Outer leaf-like bracts about 4 =Beggar Ticks, Bidens discoidea.= 127a. Bracts of the involucre all essentially alike in form and texture (flowers in summer and autumn) (Sunflower) --179. 127b. Bracts of the involucre in two distinct sets, differing in form or consistency or both --128. 128a. Leaves entire (3-8 dm. high; late spring and summer) --120b. 128b. Leaves serrate (late summer and autumn) (Bur Marigold) --129. 129a. Rays large and conspicuous, 2-3 cm. long (3-10 dm. high) =Bur Marigold, Bidens laevis.= 129b. Rays 1 cm. long or less --130.