Iris tenuis by Sereno Watson
TENUIS. Watson, Proc. Amer. Acad., xvii, 380. Rootstock elongated, very
slender (a line thick); leaves thin, ensiform, about equaling the stems, four to
eight lines broad; stems scarcely a foot high, 2 or 3-flowered, with two or three
bract-like leaves two or three inches long; lateral peduncles very slender, as long
as the bracts; spathes scarious, an inch long; pedicels solitary, very short; flowers
small, white marked with yellow and purple; tube two or three lines long;
segments oblong-spatulate, the sepals spreading, one and one-half inches long,
the petals shorter and emarginate; anthers as long as the filaments; styles with
narrow entire crests; capsule oblong-ovate, obtuse, nine lines long.]
Fig. 3.—Iris tenuis.
THIS pretty delicate species of Iris, Fig. 3, is a native of the Cascade
Mountains of Northern Oregon. Its long branching
rootstocks are scarcely more than a line in thickness, sending
up sterile leafy shoots and slender stems about a foot high.
The leaves are thin and pale green, rather taller than the stems,
sword-shaped and half an inch broad or more. The leaves of
the stem are bract-like and distant, the upper one or two subtending
slender peduncles. The spathes are short, very thin
and scarious, and enclose the bases of their rather small solitary
flowers, which are “white, lightly striped and blotched
with yellow and purple.” The sepals and petals are oblong-spatulate,
from a short tube, the sepals spreading, the shorter
petals erect and notched.
The peculiar habitat of this species doubtless accounts in
good measure for its slender habit and mode of growth. Mr.
L. F. Henderson, of Portland, Oregon, who discovered it in
1881, near a branch of the Clackamas River called Eagle Creek,
about thirty miles from Portland, reports it as growing in the
fir forests in broad mats, its very long rootstocks running
along near the surface of the ground, just covered by moss or
partly decayed fir-needles, with a light addition of soil. This
also would indicate the need of special care and treatment in
its cultivation. In May, 1884, Mr. Henderson took great pains
to procure roots for the Botanic Garden at Cambridge, which
were received in good order, but which did not survive the
next winter. If taken up, however, later in the season or very
early in the spring, it is probable that with due attention to
soil and shade there would be little trouble in cultivating it
successfully. The accompanying figure is from a drawing by
Mr. C. E. Faxon.