Pityrogramma trifoliata 'Salta'

(aka: Pityrogramma trifoliata, Trismeria trifoliata A1AG-103) When I first saw Trismeria trifoliata growing at 3,300' elevation in the northern Argentine province of Salta, I couldn't believe it was a fern...despite evidence to the contrary. This unusual fern is composed of 5' tall upright fronds with a contrasting black stipe. The spreading rhizomes form a large colony to 6' wide in 3 years. In the wild, Trismeria trifoliata grows in seasonally flooded low areas but has shown amazing adaptability under a variety of less-favorable garden conditions. It has taken 9 degrees F with no problem, so we are unsure of its northern hardiness limits.