Asterella californica

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Asterella californica
Asterella californica female receptacle.jpg
Asterella californica female receptacles
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Division: Marchantiophyta
Class: Marchantiopsida
Order: Marchantiales
Family: Aytoniaceae
Genus: Asterella
Species:
A. californica
Binomial name
Asterella californica
Synonyms
  • Fimbriaria californicaHampe ex Austin

Asterella californica is a complex thallic liverwort in the phylum Marchantiophyta. A. californica often grows as colonies of flat rosettes of light green, rigid thalli, with undersides dark wine-red to nearly black. The receptacles are rounded, with four lobes each bearing a single sporangium sheathed by a white tattered skirt. [1] A. californica is dioecious with separate male plants often intermingled with female plants. [2] This species is found throughout California. See Distribution information below. Asterella californica is the commonest species of the three species of Asterella occurring in California; [3] the other two species are A. bolanderi and A. palmeri . [4]

Description

Plants are pale green dorsally with purple ascending margins and dark purple undersides, thallus edges tending to curl upward exposing the dark underside when dry. [2] Thalli are simple or somewhat sparingly dichotomous, 8–25 mm long, usually 1-3 times dichotomous, the ultimate segments emarginated, obovate, obcordate, or broadly oblong, indistinctly areolate, 4–12 mm in maximum width. [5] The plants dry up during the long rainless summers, but the ends of the branches remain alive, so that each growing tip becomes the beginnings of a new plant. [6] It was found that a surprisingly large amount of the thallus remains alive, and within a few hours after the dried plants are supplied with water, the forward part of the thallus has assumed its active condition and begins to grow. In Asterella, the first antheridia were mature in about two weeks. This early development of the reproductive organs raised the question whether they might not begin their development before the close of the growing period in the spring. [6]

Reproduction

Male plants

Antheridia are clearly circumscribed, slightly elevated, strongly papillate, oval to linear-oblong, sometimes forked discs, situated in the median line of the thallus at some distance back from the apex. [5] While working on male individuals in his laboratory George Pierce observed, then measured, antherozoids–packets of ciliated sperm cells and encasing slime–being "forceably ejected" from the thallus. One may say, then, that Asterella can throw its antherozoids, under favorable conditions, to a vertical height of 14–20 cm. [7]

Macro image of male Asterella californica showing antheridia Asterella californica male plant.jpg
Macro image of male Asterella californica showing antheridia

Female plants

Each "umbrella", or archegoniophore, is clearly visible raised above the thallus of mature female plants is not itself a sporophyte but is in fact gametophyte tissue. [8] The part of the "umbrella" at the top of the stem is called the female receptacle or carpocephalum. The receptacle is initially on the thallus surface and the stalk grows to raise it. The archegonia are found on the female receptacle and initially they are in the upper surface and face upward. They are fertilized when the stem is still fairly short. The stem continues to grow and the receptacle continues to grow by centrally added tissue. This moves the fertilized archegonia outward and the receptacle eventually folds over to orient the developing sporophytes so that they face down. [9]

Peduncle straw-colored sometimes with a brown or purplish pigmentation, 1–3 cm high. Disk of receptacle green, about 5 mm across, low-hemispherical, deeply lobed, almost smooth, the lobes mostly 4 (sometimes 5). [8]

Sporophyte

Capsule circumscissile at the middle or above by an irregular line, the operculum breaking up into fragments. [8] Spores yellow, mostly 100 to 120 μm in diameter, with wavy wings 12-20 μm wide along the edges, the surface covered over more or less completely with a fine and often irregular reticulum with meshes 3-4 μm across. Elaters yellow variously curved, mostly 240-450 μm long and 12-16 μm wide. [8] The yellow spores with their distinct marginal wings, fine surface reticulation, and sparesly developed ridges on the faces are also very distinctive of the species. [8]

Taxonomy

In 1810 Palisot de Beauvais established the genus Asterella, but in 1820 Nees established the genus Fimbriaria in error. [10] The genus name Fimbriaria was used by Bolander in his catalogue of plants growing in the vicinity of San Francisco in 1870, but it is antedated by Asterella. [3] The genus name means "little star" in reference to the star-like appearance of pores in the thallus of some species as viewed from above. [1]

Distribution and habitat

Asterella californica is widespread and common on lightly shaded slopes and banks and around rock outcrops, mostly in oak forest, chaparral on desert scrub, mostly below 3000 feet (but to 7000 feet in San Bernardino County). [5] A. californica occurs throughout the Coast Ranges, western Klamath Ranges, Sacramento Valley, west slope of the Sierra Nevada, coastal Southern California and the Channel Islands, Transverse and Peninsular Ranges, western Colorado Desert; east to Arizona, north to southwestern Oregon, and south to northern Baja California. [11] Growing on mineral soil or among rocks on mineral soil on open or lightly shaded banks. [8]

Related Research Articles

<span class="mw-page-title-main">Bryophyte</span> Terrestrial plants that lack vascular tissue

Bryophytes are a group of land plants, sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. In the strict sense, Bryophyta consists of the mosses only. Bryophytes are characteristically limited in size and prefer moist habitats although they can survive in drier environments. The bryophytes consist of about 20,000 plant species. Bryophytes produce enclosed reproductive structures, but they do not produce flowers or seeds. They reproduce sexually by spores and asexually by fragmentation or the production of gemmae. Though bryophytes were considered a paraphyletic group in recent years, almost all of the most recent phylogenetic evidence supports the monophyly of this group, as originally classified by Wilhelm Schimper in 1879. The term bryophyte comes from Ancient Greek βρύον (brúon) 'tree moss, liverwort', and φυτόν (phutón) 'plant'.

<span class="mw-page-title-main">Marchantiophyta</span> Botanical division of non-vascular land plants

The Marchantiophyta are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information.

<span class="mw-page-title-main">Hornwort</span> Division of non-vascular land plants with horn-shaped sporophytes

Hornworts are a group of non-vascular Embryophytes constituting the division Anthocerotophyta. The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, hornworts have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information; the flattened, green plant body of a hornwort is the gametophyte stage of the plant.

<i>Marchantia</i> Genus of plants in the liverwort family Marchantiaceae

Marchantia is a genus of liverworts in the family Marchantiaceae and the order Marchantiales.

<i>Lunularia</i> Species of liverwort

Lunularia is a genus of liverworts whose only species is Lunularia cruciata, the crescent-cup liverwort. Lunularia is either the only genus in the order Lunulariales, or may be placed in the order Marchantiales. The name, from Latin luna, moon, refers to the moon-shaped gemma cups.

<span class="mw-page-title-main">Metzgeriales</span> Order of liverwort plants

Metzgeriales is an order of liverworts. The group is sometimes called the simple thalloid liverworts: "thalloid" because the members lack structures resembling stems or leaves, and "simple" because their tissues are thin and relatively undifferentiated. All species in the order have a small gametophyte stage and a smaller, relatively short-lived, spore-bearing stage. Although these plants are almost entirely restricted to regions with high humidity or readily available moisture, the group as a whole is widely distributed, and occurs on every continent except Antarctica.

<i>Riccia</i> Genus of liverworts

Riccia is a genus of liverworts in the order Marchantiales.

<i>Takakia</i> Genus of mosses

Takakia is a genus of two species of mosses known from western North America and central and eastern Asia. The genus is placed as a separate family, order and class among the mosses. It has had a history of uncertain placement, but the discovery of sporophytes clearly of the moss-type firmly supports placement with the mosses.

<i>Conocephalum</i> Genus of plants

Conocephalum is a genus of complex thalloid liverworts in the order Marchantiales and is the only extant genus in the family Conocephalaceae. Some species of Conocephalum are assigned to the Conocephalum conicum complex, which includes several cryptic species. Conocephalum species are large liverworts with distinct patterns on the upper thallus, giving the appearance of snakeskin. The species Conocephalum conicum is named for its cone-shaped reproductive structures, called archegoniophores. Common names include snakeskin liverwort, great scented liverwort and cat-tongue liverwort.

<i>Anthoceros</i> Genus of hornworts

Anthoceros is a genus of hornworts in the family Anthocerotaceae. It is distributed globally. Species of Anthoceros are characterized by having a small to medium-sized, green thallus that is more or less lobed along the margins.

Monoicy is a sexual system in haploid plants where both sperm and eggs are produced on the same gametophyte, in contrast with dioicy, where each gametophyte produces only sperm or eggs but never both. Both monoicous and dioicous gametophytes produce gametes in gametangia by mitosis rather than meiosis, so that sperm and eggs are genetically identical with their parent gametophyte.

<i>Cavicularia</i> Genus of liverworts

Cavicularia densa is the only species in the liverwort genus Cavicularia. The species was first described in 1897 by Franz Stephani, and is endemic to Japan, where it grows on fine moist soil.

<i>Marchantia polymorpha</i> Species of liverwort

Marchantia polymorpha is a species of large thalloid liverwort in the class Marchantiopsida. M. polymorpha is highly variable in appearance and contains several subspecies. This species is dioicous, having separate male and female plants. M. polymorpha has a wide distribution and is found worldwide. Common names include common liverwort or umbrella liverwort.

<i>Jensenia</i> Genus of liverworts

Jensenia is a bryophyte plant genus in the liverwort family Pallaviciniaceae. It has been treated as a subgenus of Pallavicinia by several authors, though a set of features seems to set it apart as a genus. The six or seven species of the genus belong to a southern, possibly Gondwana element.

<i>Pellia epiphylla</i> Species of liverworts in the family Pelliaceae

Pellia epiphylla is a species of thallose liverwort. It occurs in North America, Europe, North Africa and parts of Asia. It grows in patches in damp, sheltered places on neutral or acidic substrates. It is common on the banks of rivers, streams and ditches and also grows in wet woodland, marshes and on wet rocks.

<i>Ptilidium</i> Genus of liverworts

Ptilidium is a genus of liverwort, and is the only genus in family Ptilidiaceae. It includes only three species: Ptilidium californicum, Ptilidium ciliare, and Ptilidium pulcherrimum. The genus is distributed throughout the arctic and subarctic, with disjunct populations in New Zealand and Tierra del Fuego. Molecular analysis suggests that the genus has few close relatives and diverged from other leafy liverworts early in their evolution.

<i>Sphaerocarpos texanus</i> Species of liverwort

Sphaerocarpos texanus, the Texas balloonwort, is a species of liverwort in the Sphaerocarpaceae family, found in the Americas, northern Africa and Europe.

Petalophyllum, or petalwort, is a genus of liverworts in the order Fossombroniales.

<i>Cryptomitrium tenerum</i> Species of liverwort

Cryptomitrium tenerum is a species of liverwort native to North America. It is the only representative of its genus on the continent.

<i>Monoclea forsteri</i> Species of liverwort

Monoclea forsteri is one of the two species in the thallose liverwort family Monocleaceae. It is dioicous with the capsule dehiscing with a single longitudinal slit. Endemic and widely distributed throughout New Zealand, it is also the country's largest thalloid liverwort. Hooker described the species in 1820. The holotype is in the British Museum.

References

  1. 1 2 Schofield, W.B. (2002). Field Guide to Liverwort Genera of Pacific North America. University of Washington Press: Global Forest Society. p. 59. ISBN   978-0-295-98194-9.
  2. 1 2 Hicks, Marie (20 March 2003). "Bryophyte Flora of North America, Provisional Publication". Missouri Botanical Garden. Archived from the original on 6 April 2019. Retrieved 6 April 2019.
  3. 1 2 Haupt, Arthur, W. (1929). "Studies in Californian Hepaticae. I. Asterella californica". Botanical Gazette. 87 (2): 302–318. doi:10.1086/333935. JSTOR   2556462. S2CID   84645949.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  4. ↑ Kellman, Ken; Doyle, Bill (2015). "California County Lists of Liverworts and Hornworts". California Native Plant Society Bryophyte Chapter.
  5. 1 2 3 Howe, M. (1899). "The Hepaticae and Anthocerotes of California". Memoirs of the Torrey Botanical Club. 7: 1–208. hdl: 2027/nyp.33433010770398 . JSTOR   43392211.
  6. 1 2 Campbell, D. (1904). "Resistance of Drought by Liverworts". Torreya. 4 (6): 81–86. JSTOR   40594297.
  7. ↑ Peirce, George J. (June 1902). "Forcible Discharge of the Antherozoids in Asterella californica". Bulletin of the Torrey Botanical Club. 29 (6): 374–382. doi:10.2307/2478601. JSTOR   2478601.
  8. 1 2 3 4 5 6 Evans, Alexander (1920). "The North American species of Asterella". Contributions from the United States National Herbarium. 20 (8). hdl:10088/26991.
  9. ↑ "Life cycle - sporophyte - liverwort - bryophyte". www.anbg.gov.au. Retrieved 2019-04-05.
  10. ↑ Underwood, Lucien (1895). "Notes on Our Hepaticæ. III. The Distribution of the North American Marchantiaceæ". Botanical Gazette. 20 (2): 59–71. doi:10.1086/327151. JSTOR   2464017. S2CID   84709073.
  11. ↑ Whittemore, Alan (1982). "The Thallose Liverworts of California" (PDF). Thesis– via Humboldt State University.
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