Our native passionflower, Passiflora Incarnata attracts them as well.
Maypop (Passiflora incarnata) It will double duty for you for the bees as well as the Gulf Fritillary butterflies. Vitex tree,
Vitex (Vitex agnus-castus 'Shoal Creek') will also attract them. The big giant bumbles love this. Shoal Creek is the one I have and it blooms from spring till fall.
