Iris tenuis

S. Watson

Proc. Amer. Acad. Arts 17: 380. 1882.

Common names: Clackamas iris
EndemicConservation concern
Treatment appears in FNA Volume 26. Treatment on page 378. Mentioned on page 373.

Rhizomes superficial or very shallow, cordlike portion 1–2 dm × 2 mm, expanding to 10–15 mm diam., nodes with brown, scalelike leaves and few to no roots. Stems 1–2-branched, 3–3.2 dm. Leaves: basal with blade pale green, 3.2 dm × 1.5 cm, margins scarious basally, apex acute, proximal 2 semi sheathing, blade 5 cm, scarious; cauline 1–2, sheathing branch and stem for ca. 1/2 their length, blade ca. 5 cm, semimembranous. Inflorescences 2–3-branched, each unit with single flower, all borne at approximately the same level; spathes 2–3 cm × 5 mm, subequal, scarious except basally and along midrib. Flowers: perianth white or blue tinged with deep violet lines; floral-tube funnelform, 0.3 cm; sepals oblong-spatulate, 2.8 × 1 cm, apex deeply emarginate, signal an inconspicuous crest with low, yellow, undissected ridge; petals bluish white, oblanceolate-spatulate, base gradually attenuate into claw; ovary elliptical, 0.4–0.7 cm; style 1.8 cm, crests broadly obovate, 0.7 cm, margins erose; stigmas triangular-acuminate, margins entire; pedicel 0.4–1 cm, not lifting flower clear of spathes. Capsules depressed-globose, roundly triangular, 0.9–1.5 × 1.2 cm. Seeds pale-brown, with whitish raphe, D-shaped, pitted. 2n = 28.


Phenology: Flowering May.
Habitat: Open, wooded slopes in leafy soil with Douglas fir and dense shrubs

Discussion

Of conservation concern.

Iris tenuis was originally placed in ser. Californicae, but R. C. Foster (1937) stated, “It is with some hesitation that I leave it in association with them. The broad, pale green leaves are much like those of a giant I. cristata.” F. H. Smith and Q. D. Clarkson (1956) said, “It clearly does not belong in the subsection with the other members of the Californicae,” and Clarkson in a later treatment (1958) created a new subsection, the Oregonae, for it. L. W. Lenz (1959b) moved this species into subsect. Evansia (= sect. Lophiris), with which it shows many relationships.

Selected References

None.

Lower Taxa

None.

"decreasing" is not a number."dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property. "dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property.

... more about "Iris tenuis"
dehiscing +  and latrorse +
Norlan C. Henderson +
S. Watson +
3.2 cm32 mm <br />0.032 m <br /> (?) +
1.5 cm15 mm <br />0.015 m <br /> (?) +
attenuate +
Iris sect. Limniris +
5 cm50 mm <br />0.05 m <br /> (?) +
semimembranous +  and scarious +
additional +
cordlike +
enlarging +
0.9 cm9 mm <br />0.009 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
triangular +  and depressed-globose +
1.2 cm12 mm <br />0.012 m <br /> (?) +
Clackamas iris +
inconspicuous +
obovate +
0.7 cm7 mm <br />0.007 m <br /> (?) +
monochasial +
distinct or;partly completely connate +
hollow +  and solid +
ridged +  and terete +
0.3 cm3 mm <br />0.003 m <br /> (?) +
sessile +  and pedicellate +
fragrant +
upward-facing +
hollow +, solid +, branched +  and simple +
flattened +, terete +  and cordlike +
indehiscent +  and loculicidal +
woody;firm;cartilaginous +
Open, wooded slopes in leafy soil with Douglas fir and dense shrubs +
multicellular +
distinct +
cauline +  and basal +
scale-like +
distinct +
triangular +  and rounded +
6-angled +, 3-angled +  and terete +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1 cm10 mm <br />0.01 m <br />) +
blue tinged +  and white +
4 cm40 mm <br />0.04 m <br /> (18 cm180 mm <br />0.18 m <br />) +
differentiated +
bluish white +
reflexed +, spreading +  and erect +
oblanceolate-spatulate +
reduced +
Flowering May. +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
superficial +
expanding +
2 cm20 mm <br />0.02 m <br /> (?) +
Proc. Amer. Acad. Arts +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
expanding +
heterogeneous +
heterogeneous +
2 cm20 mm <br />0.02 m <br /> (?) +
undissected +
few to no +
tan;dark-brown +
conspicuously roughened +  and extensively corky +
pale-brown +
4 +  and 20 +
d--shaped +
reflexed +  and spreading +
oblong-spatulate +
expanding +
1 cm10 mm <br />0.01 m <br /> (?) +
persisting +
subequal +
5 cm50 mm <br />0.05 m <br /> (?) +
Endemic +  and Conservation concern +
monochasial +
1-2-branched +
triangular-acuminate +
3-lobed +  and filiform +
1.8 cm18 mm <br />0.018 m <br /> (?) +
Undefined sect. Evansia +
Iris tenuis +
Iris sect. Lophiris +
species +
connate +  and distinct +
scarious +
spathaceous +  and more-flowered +
obscure;prominent +
indehiscent +
hardened +  and papery +
unequal +