Chracter Koulium Psammogeton Aphanopleura Pimpinella
Habit Annual Annual Annual Biennial /perennial
Root Thick, deep yellow Thick, white to pale Thin, white to pale Thick, white to yellow
Bracts (number) bracts 3-5 Bracts 5-8 Bracts 2-5 Bracts 0-7
Bracteoles (number) bracteoles 5-6 Bracteoles 6-6 Bracteoles 5-6 Bracteoles 0-5
Petiole base Narrowly sheathy Conspicuously sheathy Narrowly sheathy Minutely sheathy
Rays (number) Rays 3-10 Rays 2-20 Rays 5-10 Rays 4-16
Petals (indumentum) margins and outside hairy Glabrous margins and outside hairy Glabrous Glabrous Glabrous
Stigma linear or nearly so Capitate Capitate Capitate
Carpophore Bifid Bifid Bifid Entire bifid or bipartite
Fruit (upper portion) Conspicuously broader Slightly narrow Slightly narrow Slightly narrow
Vittae (furrow of fruit) One One One Two or three
Fruit ridges Obscure Winged or elevated Rounded or obscure Obscure or conspicuous
Mericarp (outer face) Dorsally compressed Dorsally compressed Laterally compressed Laterally compressed
Fruit hair type Simple with few T-shaped T-shaped T-shaped T-shaped