Comparison Table - Section Viornae
| Distribution | Habit | Flower Color | Flower Position | Leaf Dissection | Venation | Leaf Texture | Notes | |
| addisonii | NC Virginia: Botetourt, Montgomery, Roanoke, Rockbridge Counties | erect, < 1 m | purple to purplish-red, whitish toward tip
 |
mostly terminal | simple, or distal leaves 1-pinnate | not reticulate, not raised | thin | back of leaflets glaucous and glabrous |
| carrizoensis | NE Texas: Cherokee, Smith, Van Zandt Counties | viny, > 1 m | yellowish- cream, lilac-tinged toward base
 |
mostly axillary | 1-pinnate to pinnate-ternate, proximal leaflets commonly lobed or 3-foliate | reticulate, raised | leathery | back of leaflets glaucous and glabrous |
| crispa | E & S USA: AL, AR, FL, GA, IL, KY, LA, MO, MS, NC, OK, SC, TN, TX, VA | viny, > 1 m | pale blue, pale pink or bluish-purple to violet-purple
 |
mostly terminal | 1-pinnate to pinnate-ternate, rarely simple or 3-foliate, proximal leaflets commonly lobed | not reticulate, not raised | thin | |
| glaucophylla | CS & SE USA: AL, AR, FL, GA, KY, LA, MO, MS, NC, OK, SC, TN, VA | viny, > 1 m | cherry red to reddish-purple
 |
mostly axillary | 1-pinnate to pinnate-ternate, proximal leaflets commonly lobed or 3-foliate | not reticulate, not raised | thin | back of leaflets glaucous and glabrous |
| morefieldii | N Alabama: Madison County S Tennessee: Franklin County |
viny, > 1 m | pinkish, greenish toward tip
 |
mostly axillary | 1-pinnate to pinnate-ternate, proximal leaflets commonly lobed | reticulate, not raised | thin | Stems are cobwebby tomentose/ villous pubescent. Bracts at or close to the base of peduncle. |
| pitcheri | C & S USA: AR, IA, IL, IN, KS, KY, MO, MS, NE, NM, OK, TN, TX | viny, > 1 m | purplish-blue to purplish-violet to brick red, sometimes whitish toward tip
 |
mostly axillary | 1-pinnate to pinnate-ternate, many simple, proximal leaflets commonly lobed or 3-foliate | reticulate, raised * | leathery or thin | Mature fruits with glabrous or silky tails, not feathery. *Tertiary and quaternary veins scarcely or not raised. |
| reticulata | S & SE USA: AL, AR, FL, GA, KY, LA, MS, OK, SC, TX | viny, > 1 m | pale lavender to purple, greenish toward tip
 |
mostly axillary | 1-pinnate to pinnate-ternate, proximal leaflets commonly lobed or 3-foliate | finely reticulate, raised | leathery | Mature fruits with feathery tails. Quaternary veins distinctly raised. |
| texensis | C Texas: Bandera, Blanco, Comal, Kendall, Kerr, Llano, Travis Counties | viny, > 1 m | scarlet to rose-red
 |
mostly axillary | 1-pinnate to pinnate-ternate, proximal leaflets commonly lobed or 3-foliate | reticulate, raised | leathery | back of leaflets glaucous and glabrous |
| versicolor | C USA: AL, AR, KY, MO, OK, TN, TX | viny, > 1 m | purplish-red to bluish- lavender, creamy or greenish toward tip
 |
mostly axillary | 1-pinnate, proximal leaflets mostly unlobed, occasionally 2-3 lobed | reticulate, raised | leathery | back of leaflets glaucous and glabrous |
| viorna | EC, NE & S USA: AL, AR, DC, DE, GA, IL, IN, KY, MD, MO, MS, NC, OH, PA, SC, TN, VA, WV | viny, > 1 m | pale lavender to reddish purple, cream-yellow toward tip
 |
mostly axillary | 1-pinnate, some simple, proximal leaflets commonly lobed or 3-foliate | not reticulate, not raised | thin | Stems without cobwebby pubescence, bracts well above base of peduncle/ pedicel. |
Sources:
Estes, D. A new narrowly endemic species of Clematis from Northeastern Texas. Sida 22(1):65–77, 2006. (pdf)
Grey-Wilson, C. Clematis The Genus. Timber Press, OR. Pp. 200-216, 2000.
Pringle, J.S. Clematis. In: Flora of North America. Volume 3. www.efloras.org, 2007.