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.
2 Leaflets 15-43 per pinna. | |
3 Pinnae 4-7 pairs per leaf; fruits breaking into 10-15 segments; [ s. TX southwards] | |
3 Pinnae 5-16 (-22) pairs per leaf; fruits breaking into 14-21 segments; [naturalized, in our region known from FL] | |
2 Leaflets (3-) 4-12 per pinna. | |
4 Pinnae 1-8 pairs per leaf; leaflets 5-12 per pinna; fruits slightly to somewhat constricted between segments, but not jointed into segments | |
4 Pinnae 1-3 (-4) pairs per leaf; leaflets (3-) 4-7 per pinna; fruits strongly constricted between seeds, jointed and breaking into segments | |
1 Herbs, sometimes suffrutescent, trailing, sprawling, or climbing (by means of recurved, catclaw prickles). | |
6 Pinnae (1) 2-5 pairs per leaf; leaflets either 10-25 per pinna or 4-6 per pinna; fruits not quadrangular, the valves breaking into segments. | |
6 Pinnae 3-8 (-11) pairs per leaf; leaflets 5-25 per pinna; fruits normally quadrangular (sometimes compressed in M. roemeriana) because of widening of the replum, the valves remaining intact and not separating. | |
8 Leaflets (9-) 10-17 (-19) per pinna. | |
12 Valves of the pod 3-6 mm wide, distinctly wider than the replum; [on limestone, caliche, and other calcareous substrates; sc. OK south through nc. TX to the Edwards Plateau, extending slightly into se. TX Coastal Plain] | |
12 Valves of the pod as wide as or narrower than the replum; [collectively widespread, usually not on calcareous substrates, at least not in TX] | |
13 Pinnae 4-8 pairs per leaf; seeds 3.2-5.2 mm long; [east of the Mississippi River, VA and KY south to s. FL and e. LA] | |