Cheilanthes gracillima

D. C. Eaton in Emory

in Emory,Rep. U.S. Mex. Bound. 2: 234. 1859.

Common names: Lace fern
Endemic
Synonyms: Myriopteris gracillima (D. C. Eaton) J. Smith
Treatment appears in FNA Volume 2.

Stems short-creeping, 4–8 mm diam.; scales uniformly brown or with poorly defined, dark, central stripe, linear-lanceolate, straight to slightly contorted, loosely appressed, persistent. Leaves clustered, 5–25 cm; vernation noncircinate. Petiole dark-brown, rounded adaxially. Blade linear-oblong, 2–3-pinnate at base, 1–2.5 cm wide; rachis rounded adaxially, with scattered linear scales, not pubescent. Pinnae not articulate, dark color of stalk continuing into pinna base, basal pair not conspicuously larger than adjacent pair, usually equilateral, appearing sparsely pubescent or glabrous adaxially. Costae green adaxially for most of length; abaxial scales multiseriate, linear, truncate at base, inconspicuous, the largest 0.1–0.4 mm wide, loosely imbricate, not concealing ultimate segments, long-ciliate, cilia usually confined to base. Ultimate segments oblong or rarely oval, beadlike, the largest 1.5–3 mm, abaxially densely covered with branched hairs and small, ciliate scales, adaxially with scattered, branched hairs or glabrescent. False indusia marginal, slightly differentiated, 0.05–0.25 mm wide. Sori ± continuous around segment margins. Sporangia containing 64 spores.


Phenology: Sporulating summer–fall.
Habitat: Cliffs and rocky slopes, usually on igneous substrates
Elevation: 800–3000 m

Distribution

V2 467-distribution-map.gif

Alta., B.C., Calif., Idaho, Mont., Nev., Oreg., Utah, Wash.

Discussion

Cheilanthes gracillima is a well-marked species, but it apparently hybridizes with C. intertexta (see reticulogram) to produce plants of intermediate morphology with malformed spores that have been called C. gracillima var. aberrans M. E. Jones (A. R. Smith 1974).

Selected References

None.

Lower Taxa

None.

... more about "Cheilanthes gracillima"
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
Michael D. Windham +  and Eric W. Rabe +
D. C. Eaton in Emory +
glabrous +  and pubescent +
not conspicuously larger than adjacent pair +
cuneate +, truncate +  and rounded +
scaly rarely glabrous adaxially pubescent +  and glabrous +
linear-oblong +
1cm;2.5cm +
Lace fern +
Alta. +, B.C. +, Calif. +, Idaho +, Mont. +, Nev. +, Oreg. +, Utah +  and Wash. +
800–3000 m +
0.005 cm0.05 mm <br />5.0e-5 m <br /> (0.025 cm0.25 mm <br />2.5e-4 m <br />) +
yellow +  and white +
obcordate;reniform +
Cliffs and rocky slopes, usually on igneous substrates +
monomorphic +
clustered;widely scattered +
recurved +  and reflexed +
noncircinate +  and circinate +
5 cm50 mm <br />0.05 m <br /> (25 cm250 mm <br />0.25 m <br />) +
denticulate +  and entire +
glabrous +, scaly +  and pubescent +
Sporulating summer–fall. +
not articulate +
in Emory,Rep. U.S. Mex. Bound. +
not pubescent +
with poorly defined , dark , central stripe;brown +
straight +
persistent +
linear-lanceolate +
yellowish +, brown +  and black or gray +
cristate +  and tetrahedral-globose +
dark colored +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
ascending +  and horizontal +
Myriopteris gracillima +
Cheilanthes gracillima +
Cheilanthes +
species +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0 cm0 mm <br />0 m <br /> (?) +  and 0.4 cm4 mm <br />0.004 m <br /> (?) +
crescent--shaped +  and roundish +
branched +  and anastomosing +