We are enjoying the rare Penstemon baccharifolius this summer in our high/dry crevice garden. This species is native to limestone ledges up to 6,500′ elevation from the Edwards plateau in Texas south into Northern Mexico. This species hates our summer rains, and we had given up on growing this until we built our alkaline crevice garden a few years ago. Now it thrives, growing in 3′ deep Permatill gravel.
To identify plants that are new to us, we start with the time-tested step of determining how close plants look to relatives we already know. This comes first, before we dive into floral dissection, etc. In most cases, we can get pretty close to a correct id, since we’ve grown and seen such a large number of plants. Two plants that threw us completely off the trail when we first saw them, are flowering now in the crevice garden here at JLBG.
The first, below, is Digitalis obscura, the Spanish Foxglove. I’d have lost big had I wagered on its identity when I first saw this, since I would have bet the farm that it was a penstemon, since the flowers and foliage share such an amazing resemblance to that genus. It’s taken us years to find a spot well-drained enough for this to survive in our rainy, humid, climate, but the wait was worth it.
The second plant that doesn’t seem to fit its genus is also flowering now in the crevice garden…Penstemon ambiguous. This Southwest/Great Basin native, known as sand beardtongue, looks nothing like other members of the penstemon family, which are usually easily recognizable at first glance. Instead, it could easily be mistaken for a phlox. This is our third year for this gem, so perhaps this may appear in our nursery offerings one day.