Adiantum jordanii

Müller Halle

Bot. Zeitung 1864: 26. 1864.

Common names: California maidenhair
Illustrated
Treatment appears in FNA Volume 2.

Stems short-creeping; scales reddish-brown, concolored, margins entire. Leaves arching or pendent, clustered, 30–45 cm. Petiole 1–1.5 mm diam., glabrous, not glaucous. Blade lanceolate, pinnate, 20–24 × 8–10 cm, gradually reduced distally, glabrous; proximal pinnae 3 (–4) -pinnate; rachis straight, glabrous, not glaucous. Segment stalks 1–4 mm, with dark color ending abruptly at segment base. Ultimate segments fan-shaped, not quite as long as broad; base truncate or broadly cuneate; margins of fertile segments unlobed but very narrowly incised, sterile segments with margins lobed, denticulate; apex rounded. Indusia transversely oblong, 3–10 mm, glabrous. Spores mostly 40–50 µm diam. 2n = 60.


Phenology: Sporulating early spring–midsummer.
Habitat: Seasonally moist, shaded, rocky banks, canyons, and ravines
Elevation: 0–1000 m

Distribution

V2 522-distribution-map.gif

Calif., Oreg., Mexico in Baja California

Discussion

Adiantum jordanii occasionally hybridizes with A. aleuticum where their ranges overlap in northern California, yielding the sterile hybrid Adiantum × tracyi C. C. Hall ex W. H. Wagner. Adiantum × tracyi, morphologically intermediate between its parental species, can be distinguished from A. jordanii by its broadly deltate leaf blade that tapers abruptly from the 4(–5)-pinnate base to a 1-pinnate apex. It is best separated from A. aleuticum by leaf blades with a strong rachis, and by ultimate blade segments that are less than twice as long as broad. Adiantum × tracyi shows 59 univalents at metaphase; its spores are irregular and misshapen (W. H. Wagner Jr. 1962).

Selected References

None.

Lower Taxa

None.
... more about "Adiantum jordanii"
Cathy A. Paris +
Müller Halle +
cuneate +  and truncate +
20 cm200 mm <br />0.2 m <br /> (24 cm240 mm <br />0.24 m <br />) +
lanceolate +
reduced +
8cm;10cm +
California maidenhair +
Calif. +, Oreg. +  and Mexico in Baja California +
0–1000 m +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
yellow +  and white +
obcordate;reniform +
Seasonally moist, shaded, rocky banks, canyons, and ravines +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
monomorphic +
densely clustered;closely spaced +
recurved +  and reflexed +
noncircinate +  and circinate +
30 cm300 mm <br />0.3 m <br /> (45 cm450 mm <br />0.45 m <br />) +
dentate +, erose-ciliate +  and entire +
chestnut-brown;dark purple or blackish +
not glaucous +  and glabrous +
Sporulating early spring–midsummer. +
Bot. Zeitung +
not glaucous +  and glabrous +
concolored;reddish-brown +
persistent +
linear-lanceolate +  and lanceolate +
incised +  and unlobed +
sterile +  and fertile +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Illustrated +
yellowish-brown +  and yellow +
1 +, 32 +  and 64 +
tetrahedral-globose +
suberect +  and long-creeping +
shiny +  and dull +
Adiantum jordanii +
Adiantum +
species +
0.3 cm3 mm <br />0.003 m <br /> (?) +  and 2.9 cm29 mm <br />0.029 m <br /> (?) +
1 +  and several +
crescent--shaped +  and roundish +
anastomosing +  and simple +
conspicuous +
on rock +  and terrestrial +