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Adiantum jordanii

(California Maidenhair Fern Adiantum Jordanii)

Common Names

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Common Names in English:

California Maidenhair, California Maidenhair Fern Adiantum Jordanii, California Maidenhair Fern, Jordan Maidenhair-Fern

Description

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Family Pteridaceae

Genera ca. 40, species ca. 1000 (13 genera, 90 sp: worldwide.

Considerable disagreement exists concerning the circumscription and proper name of this family . The taxa comprising the Pteridaceae in this treatment were assigned to the Sinopteridaceae and Pteridaceae by D. B . Lellinger (1985) and were included in five families by R. E. G. Pichi-Sermolli (1977). The broad concept followed here is similar (except for the exclusion of Ceratopteris ) to that espoused by R. M. Tryon and A. F. Tryon (1982), who applied the name Pteridaceae to the group. Until very recently, the newer name Adiantaceae was more commonly used.

As represented in North America, Pteridaceae comprise three major evolutionary lines (the adiantoids, the pteroids, and the cheilanthoids). Characteristics holding the family together include abaxial (usually submarginal ) sori that lack indusia or are protected by a reflexed or revolute leaf margin , spores that are usually globose-tetrahedral and trilete, and chromosome base numbers of 30 or 29 (rarely 27). The xeric-adapted members of the family (particularly the cheilanthoids) have undergone extensive parallel and convergent evolution, and they have frustrated attempts to produce a natural generic classification based on macromorphologic characteristics alone. Although some workers have aggregated species into a few large genera (e.g. , J. T. Mickel 1979b), most tend to recognize smaller segregate genera based on a combination of morphologic, chromosomal, and biochemical data. The latter approach seems to provide a more useful, evolutionarily informative classification and is the one adopted here. Aspidotis and Notholaena are maintained here as distinct from Cheilanthes, and three recently described genera ( Argyrochosma, Astrolepis, and Pentagramma ) have been incorporated into the treatment. The reasons for these changes in generic circumscription are discussed under the individual genera.[1]

Genus Adiantum

Plants terrestrial or on rock. Stems short- to long-creeping or suberect, branched; scales deep tawny yellow to dark reddish brown [black], concolored or bicolored , linear-lanceolate to lanceolate, margins entire , erose-ciliate, or minutely dentate . Leaves monomorphic to somewhat dimorphic , densely clustered to closely spaced [distant ], 15--110 cm. Petiole chestnut brown to dark purple or blackish, with single groove adaxially, glabrous , hispid , or strigose , with 1 or 2 vascular bundles . Blade lanceolate, ovate , trowel-shaped, or fan-shaped, 1--4(--9) -pinnate proximally, membranaceous to papery , both surfaces commonly glabrous (2 species with scattered hairs ), adaxially dull or shiny, not striate ; rachis straight or flexuous . Ultimate segments subsessile to short-stalked (stalks terminating in cupulelike swelling at base of pinna in A. tenerum ), round, fan-shaped, rhombic , or oblong , 3--29 mm wide; base truncate to cuneate, free from costa; stalk dark, often lustrous ; fertile segments with marginal lobes recurved to form false indusia. Veins of ultimate segments conspicuous , free, ± dichotomously forking near base and well above segment base [anastomosing in a few tropical species], parallel distally. False indusia light gray-green or brown to dark brown, narrow, 0.6--1 mm wide, marginal, concealing sporangia until sporangia dehisce. Sporangia submarginal, borne along or sometimes also between veins on abaxial surface of false indusium, paraphyses and glands absent. Spores yellow or yellowish brown, tetrahedral-globose, trilete, rugulate to rugose or tuberculate , equatorial ridge absent. x = 29, 30.

Species ca. 150--200: nearly worldwide except at latitudes greater than 60°.

Most diverse in Andean South America, Adiantum is primarily a tropical genus; of the nine species occurring in the flora , A. melanoleucum, A. tenerum, and A. tricholepis are strictly subtropical . Adiantum hispidulum occurs only as an escape from cultivation. The genus is absent from dry areas in the interior of the continent.

Adiantum is a very clearly circumscribed genus of ferns, the character state "sporangia borne on abaxial surface of false indusium" being both necessary and sufficient to define it. Within this large and widespread genus, however, species relationships are mostly unknown. An evolutionary classification of the group is indeed much needed (R. M. Tryon and A. F. Tryon 1982).[2]

Physical Description

Species Adiantum jordanii

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. 2 n = 60. Sporulating early spring--midsummer. [source]

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). [source]

Habit: Forb/herb

Flowers: Flower Color: inconspicuous, none

Size/Age/Growth

Size: 18-24" tall.

Habitat

Seasonally moist, shaded, rocky banks, canyons , and ravines ; 0--1000 m [3].

Typically found at an altitude of 0 to 2,848 meters (0 to 9,344 feet).[4]

Biology

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Reproduction

Duration: Perennial

Growth

Sunlight: Sun Exposure: Partial to Full Shade.

Temperature: Cold Hardiness: 8a, 8b, 9a, 9b, 10a, 10b. (map)

Taxonomy

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Unambiguous Synonyms

  1. Adiantum Jordani
  2. Adiantum jordani Mnll. Berol.

Notes

Name Status: Accepted Name . Latest taxonomic scrutiny: 15-Mar-2000

Similar Species

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Members of the genus Adiantum

There are approximately 636 species in this genus. Here are just 100 of them:

A. abscissum · A. achilleifolium · A. acinaciforme · A. acrocarpon · A. aculeatum · A. aculeolatum · A. acuminatum · A. adiantoides · A. aemulum · A. aethiopicum (Common Maidenhair Fern) · A. aethiopicum var. nodosa · A. aetiopi · A. affine · A. africanum · A. alarconianum · A. alatum · A. aleuticum (Aleutian Maidenhair-Fern) · A. aleuticum 'Imbricatum' · A. aleuticum 'Japonicum' · A. aleuticum 'Laciniatum' · A. aleuticum 'Miss Sharples' · A. aleuticum subpumilum · A. aleuticum 'Subpumilum' · A. amabile · A. amazonicum · A. amblyopteridium · A. amelianum · A. americanum · A. amoenum · A. amplum · A. anceps (Double Edge Maidenhair) · A. andicola · A. aneitense · A. angustatum · A. angustifolium · A. annamense · A. apalophyllum · A. arcanum · A. arcuatum · A. argutum · A. aristatum · A. asarifolium · A. asperum · A. assimile · A. atroviride · A. aubertii · A. auriculatum · A. australe · A. baenitzii · A. balansae · A. balfourii · A. bausei · A. bellum (Bermuda Maidenhair Fern) · A. bessoniae · A. birkenheadii · A. blumenavense · A. boliviense · A. bonatianum · A. bonii · A. bonplandii · A. borbonicum · A. boreale · A. brasiliense · A. braunii · A. breviserratum · A. caffrorum · A. cajennense · A. cajennense var. stenophyllum · A. calcareum · A. candatum · A. cantoniense · A. capense · A. capillaceum · A. capillaris-veneris · A. capillatum · A. capillis-veneris · A. capillium-veneris · A. capillius-veneris · A. capillus (Common Maidenhair) · A. capillus-junonis · A. capillus-venaris · A. capillus-venensis · A. capillus-veneri · A. capillus-veneris (Southern Maidenhair Fern) · A. capillus-veneris 'Banksianum' · A. capillus-veneris 'Cornubiense' · A. capillus-veneris 'Imbricatum' (Imbricatum Southern Maidenhair Fern Adiantum Capillus-Veneris) · A. capillus-veneris L. 'Fimbriatum' (Fimbriatum Southern Maidenhair Fern Adiantum Capillus-Veneris) · A. capillus-veneris 'Mairisii' · A. capillus-veneris 'Pointonii' · A. capillus-veneris var. fissum · A. capillus-veneris var. trifidum · A. capillus-venerus · A. capillusveneris · A. capillus gorgonis · A. capilus-veneris · A. capitus-junosis · A. cardiochlaena · A. caryotideum · A. cassioides

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal February 01, 2008:

Identifiers

Footnotes

  1. Michael D. Windham "Pteridaceae". in Flora of North America Vol. 2. Oxford University Press. Online at EFloras.org. [back]
  2. Cathy A. Paris "Adiantum". in Flora of North America Vol. 2. Oxford University Press. Online at EFloras.org. [back]
  3. "Adiantum jordanii". in Flora of North America Vol. 2. Oxford University Press. Online at EFloras.org. [back]
  4. Mean = 402.080 meters (1,319.160 feet), Standard Deviation = 347.130 based on 3,168 observations. Altitude information for each observation from British Oceanographic Data Centre. [back]
Last Revised: 2009-04-24