Drynaria sp. MD 17-69

Our collection from Vietnam of this fascinating epiphytic genus.  This was growing on a tree trunk on a small limestone ridge populated by a mix of frost-tolerant and frost-intolerant species.  The hardiness of this remains to be tested here - maybe a warm zone 8b? - it made it through the admittedly mild first winter here so at least some frost hardiness.  Excellent drainage is likely key to improved hardiness and ours is in a tufa wall.  Spreads by creeping rhizomes and has dimorphic leaves with persistent basal fronds and fertile foliage fronds though only the latter have been produced on ours thus far.