Tsus-sima holly fern, Korean rock fern
Epithet means "from Tsus-sima Island."
Evergreen, 1 to 1V2 ft. (30 to 45 cm).Zones 6 to 9. Apogamous.
description: The rhizome is erect. Grooved stipes with dark brownish black scales are between one-fourth and one-
Polystichum tsus-simense in the Duryee garden. Golden-hued scales on the young fronds of Polystichum vestitum.
third of the frond length. Blades are lanceolate, bipinnate, and black-green with even darker veins. Fifteen to twenty pairs of pinnae support spine-tipped pinnules that are clearly separate and have a hint of a stalk. Sori with peltate indusia are medial.
range and habitat: Korea, China, Japan, Thailand, and Indochina are all homelands for this species which grows in forests and on rocky slopes.
culture and comments: Polystichum tsus-simense arrived in North America via the florist trade where it is a popular finishing touch for flowers in boutonnieres. Garden hardiness and worthiness came as an unexpected bonus. It is a tidy low-growing trimming for shady perennial beds as well as a very suitable low-maintenance choice for indoor culture. Current botanical research places this as a sister species or even as synonymous with P. luctuosum. However, the pinnules on the latter are partially attached to the pinnae (adnate) rather than separated. In addition P. tsus-simense is not indigenous to limestone habitats whereas it is the location of choice for P. luctuosum. I have always been what is classified as a "lumper" as opposed to a "splitter" in separating or grouping species. (Age will do this.) In this instance, however, I will yield to the "splitters" in order to keep the traditional and familiar name P. tsus-simense from disappearing as the designated binomial for this species.
Was this article helpful?