slow growing species is noted for its giant size (30 inches high by
66 inches high), vase shaped mounds of cupped blue-green foliage.
The leaves are broadly ovate shaped, moderately corrugated and
have thick substance. It has very
tall (about 6 feet high) flower scapes with pale lavender blooms
from late July into
mid-August followed by some viable seeds.
The Hostapedia by Mark Zilis (2009), "It has proven to be an outstanding, "impact" plant
in the shade gardens throughout the U.S. H. nigrescens
makes an excellent background plant and can be a magnificent
focal point of an island bed."
The New Encyclopedia of Hostas by
Grenfell (2009) states: "Moderate growth rate...Small hostas and other
ground-covering plants can be grown at its feet...Shoots emerge
darkly colored, almost black. Scapes tower above the foliage mound."
W. George Schmid in his
Hosta Species Update on The Hosta
Library (2007) says, "H.
nigrescens...and H. ‘Tenryu’
are morphologically the same. There are slight differences in
the flower color, H. ‘Tenryu’ has white flowers shading
to a very light mauve with barely darker stripes, while H.
nigrescens has almost white flowers. The anthers of both are
bi-color purple. In this Species Update they are
considered the same.
"H.nigrescens was obtained in Japan by the late
Gus Krossa, who imported many hostas from Japan and
Europe obtaining them from academic sources and
collectors the world over. His connections to Osaka
University brought a number of wild taxa into the United
States. He numbered H. nigrescens as
B-5 and it
appeared in Summers (1972) as
Summers No. 111;