Don't think so. Graham Nicholls used to sell E. howardii and the American form of E. nanum but his nursery is now closed. Your best bet is to check the members stand at a show as seed is sometimes set in cultivation and I have in the past (albeit not recently) sold plants there, as have one or two other people. Also, nanum is occasionally in both the AGS and SRGC seed distribution but you'd need to be pretty high up the priority list as it will always be in short supply and oversubscribed.
Paul R
