Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.

Click images to enlarge and show more photo credit.

Key to Aristolochia

Aristolochiaceae

Aristolochia

Copy permalink to share

(c) Semmling, Bonnie - CC-BY
1 Low, erect or ascending herb or (Aristolochia pentandra) a twining herbaceous vine; leaves 0.5-6.5 cm wide.
(c) Semmling, Bonnie - CC-BY
(c) Wong, Michelle - CC-BY
  2 Leaf bases cuneate; gynoecium and androecium 5-merous
© Roger L. Hammer
  2 Leaf bases cordate; gynoecium and androecium 3-, 5-, or 6-merous.
© Roger L. Hammer
© Roger L. Hammer
    3 Twining herbaceous vine; gynoecium and androecium 5-merous
(c) Whitson, M. - CC-BY
    3 Erect or ascending herb; gynoecium and androecium 3- or 6-merous.
(c) Whitson, M. - CC-BY
(c) Baratta, Eric - CC-BY
      4 Leaf blade as wide as long, or wider than long; leaf venation palmate
(c) Fleming, Gary P.
(c) Hill, Sonnia
      4 Leaf blade narrower than long; leaf venation pinnate (3-veined from the base, pinnate above)
1 Woody, twining vine; leaves 3-35 cm wide
(c) Stuart, Will
(c) Cressler, Alan M.
        5 Gynostemium lobes 3; calyx limb 3-lobed, the lobes similar in size and shape and arranged radially around the tube orifice at 120 degree angles
(c) Hammer, Roger L.
        5 Gynostemium lobes 6; calyx limb 1- or 2-lobed (if 2-lobed, the lobes dissimilar in shape)
(c) suzannehale - CC0
             7 Calyx limb 1-lobed, orbicular, 10-50 cm in diameter
(c) suzannehale - CC0
               8 Calyx limb about 10 cm in diameter, notched at the bottom
(c) Vinod, Paulmathi - CC-BY
               8 Calyx limb 20-50 cm in diameter, attenuate at the bottom into an elongate dangling appendage
 Aristolochia grandiflora
             7 Calyx limb 2-lobed, the lower lanceolate, acuminate, folded longitudinally and bird-beak-like, 10-20 cm long, the upper with a parallel-sided claw and orbicular tip.
(c) Machado, Siddarth - CC-BY
(c) Machado, Siddarth - CC-BY
                 9 Upper lobe of calyx limb 14-18 cm wide, with ruffled margin, pendent below the lower lip
(c) Vinod, Paulmathi - CC-BY
                 9 Upper lobe of calyx limb 4-5 cm wide, not ruffled, erect over the lower lip