Pachypodium ambongense is flowering at a Japanese succulent shop here in Tokyo. They had smaller ambongense but I forgot to take pictures in my previous visit and they're now gone. Ambos are Amazon.com: Easy to Grow Spider Plant Variegated 2 Full Size Potted Plants Large Established Houseplants in 4" Quart Pots Indoor Outdoor, Low Maintenance, Air Purifying (Not Starter Plugs) : Patio, Lawn Cactus and Succulent Potting Mix Fantastic Gardens Set seeds on the right path with homemade planting medium Newsroom Oregon State University Cacti Organ Pipe Cactus National Monument (U.S. National Park Service)