5 flower center column, outer parts usually pointing outward and upward
5 flower center column, outer parts usually turned downward
99. Spider antelope horns. Asclepias asperula var. decumbens
100. Green antelope horns. Asclepias viridis
101. Showy milkweed. Asclepias speciosa
103. Engelmann's milkweed. Asclepias engelmanniana
104. Green milkweed. Asclepias viridiflora
107. Broadleaf milkweed. Asclepias latifolia
102. Sand milkweed. Asclepias arenaria
106. Plains milkweed. Asclepias pumila
[5 flower] [Open faced flowers]