Flora of the Southeastern United States
2022 Edition

Colors

Data mode

Key to Hydrophyllum

1 Principal cauline leaves palmately lobed, maple-like, differing from the pinnately divided basal leaves.
..2 Sepals with small reflexed appendages exserted at each sinus of the calyx; plant biennial from a taproot; stamens exserted 1-3 mm beyond the corolla; leaf lobing relatively shallow and irregular
..2 Sepals with appendages absent or rudimentary; plant perennial from fibrous roots; stamens exserted 3-6 mm beyond the corolla; leaf lobing relatively deep and regular
1 Principal cauline leaves pinnately divided, similar to the basal leaves.
....3 Inflorescence and upper stem densely hirsute with spreading hairs 1-2 mm long; larger leaves pinnatifid with (7-) 9-13 segments, these toothed but not lobed.
......4 Tubers 0.5-3 cm long, ellipsoid or cylindric, typically producing whiplike tips, these often widely spreading and repeatedly proliferating; hairs of leaf upper surface 0.5-0.8 (-1.0) mm long (none > 1.0 mm long); corolla 10-12 mm long, lavender to almost white; [west of Mississippi River, in Interior Highlands of AR]
......4 Tubers to 10 cm long, fusiform, with slender tips to 10 cm long, not generally proliferating; hairs of upper leaf surface to 1.5 mm long (at least some > 1.0 cm long); corolla 7-10 (-12) mm long, white, greenish-white, or yellowish-white; [east of Mississippi River]
....3 Inflorescence and upper stem glabrate to strigose with appressed to ascending hairs < 0.5 mm long; larger leaves with 5-7 (-9) pinnate (or upwards, pinnatifid) segments, some of them sometimes deeply 2-lobed.
........5 Corolla medium or deep purple to maroon; lower stem glabrous to slightly (rarely moderately) pubescent with retrorse hairs; plant leafy through the summer and winter-dormant; [of low to high elevations, endemic in the Southern Appalachians, north to c. VA]
........5 Corolla white to lavender or pale purple; lower stem slightly to densely pubescent with retrorse to spreading hairs; plant leafy through the winter and summer-dormant; [of low elevations of the Piedmont, Mountains, Interior Highlands, and rarely Coastal Plain and Interior Low Plateau]