Isoëtes orcuttii

A. A. Eaton

Fern Bull. 8: 13. 1900.

Common names: Orcutt's quillwort
Synonyms: Isoëtes nuttallii var. orcuttii (A. A. Eaton) Clute
Treatment appears in FNA Volume 2.

Plants becoming terrestrial. Rootstock nearly globose 2 (–3) -lobed. Leaves deciduous, bright green, pale toward base, less than 8 cm, gradually tapering to tip, often surrounded at base by several black scales to ca. 5 mm, spirally arranged, pliant, gradually tapering to tip. Velum covering entire sporangium. Sporangium wall unpigmented. Megaspores white to gray, lustrous, 200–380 μm diam., ± smooth to obscurely tuberculate; girdle obscure. Microspores brown in mass, 20–30 μm, smooth to papillose. 2n = 22.


Phenology: Spores mature in spring.
Habitat: Vernal pools
Elevation: mostly 0–1500 m

Distribution

V2 430-distribution-map.gif

Calif., Mexico in Baja California

Discussion

Isoëtes orcuttii, a vernal pool endemic, may be difficult to distinguish from I. nuttallii, which occurs in a wider range of habitats. Plants of I. orcuttii are generally smaller than those of I. nuttallii, which has longer, thicker, less flexible leaves and larger megaspores.

Selected References

None.

Lower Taxa

None.
... more about "Isoëtes orcuttii"
several +  and 1 +
W. Carl Taylor +, Neil T. Luebke +, Donald M. Britton +, R. James Hickey +  and Daniel F. Brunton +
A. A. Eaton +
Orcutt's quillwort +
alternating +
Calif. +  and Mexico in Baja California +
mostly 0–1500 m +
Vernal pools +
pale +  and bright green +
straight +
deciduous +
recurved;erect;spreading +
tapering +
0 cm0 mm <br />0 m <br /> (8 cm80 mm <br />0.08 m <br />) +
deltate;cordiform +
0.1 cm1 mm <br />0.001 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
membranous +
white +  and gray +
less smooth +  and obscurely tuberculate +
smooth +  and papillose +
Spores mature in spring. +
branched +  and simple +
2(-3)-lobed +  and globose +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Isoëtes nuttallii var. orcuttii +
Isoëtes orcuttii +
Isoëtes +
species +
brown-streaked;completely brown +
ephemeral +, evergreen +  and perennial +