Does anyone have a reference that distinguishes Mansoa alliacea from Mansoa hymenaea? For Mansoa alliacea, I have found a description: "opposite leaves divided into two ovate leaflets, up to 15cm (6 inch) long. The leaves are bright green", from Plants & Flowers » Top Anti-Pollutant Houseplants. That's the same for M. hymenaea: "This plant can be distinguished by its strong garlic odor (which gives it the common name “Garlic vine”), compound leaves with two leaflets, three-forked tendrils, and lavender to magenta corollas (Staples & Herbst 2005)", from New plant records from O‘ahu for 2009 I have found these in two locations, thought they were new to me, but I'm told they grow in Vancouver (or maybe just one of them grows in Vancouver?). These are from Grove Farm on Kaua'i. And these are from Kapi'olani Community College in Honolulu.
Never mind. On the Bishop Museum Cook Islands Biodiversity page for Mansoa hymenaea, it lists M. alliacea as a synonum. Cook Islands Biodiversity : Mansoa hymenaea - Garlic-scented Vine I love it when some difference I can't see turns out not to be there.