Ptilidium ist eine kleine und die einzige Gattung von beblätterten Lebermoosen der Familie Ptilidiaceae.
Die Pflanzen sind olivgrün, bräunlich oder rötlich und ein- bis dreifach gefiedert. Die quer bis schräg gestellten Flankenblätter sind zweilappig, wobei der ventrale Lappen nochmals geteilt ist, sodass die Blätter mehrlappig erscheinen. Die Blattränder sind lang gewimpert. Unterblätter sind vorhanden, sie sind kleiner als die Flankenblätter und zweilappig. Die Laminazellen weisen knotig verdickte Zellecken auf. Pro Zelle sind 15 bis 40 Ölkörper vorhanden.
Die Arten sind diözisch. Die zylindrischen Perianthien sind an der Mündung kurz gewimpert. Sporenkapseln sind oval. Brutkörper werden nicht gebildet.
Die Gattung Ptilidium umfasst weltweit drei Arten, von denen zwei in Europa vorkommen.
Ptilidium ist eine kleine und die einzige Gattung von beblätterten Lebermoosen der Familie Ptilidiaceae.
Ptilidium is a genus of liverwort, and is the only genus in family Ptilidiaceae. It includes only three species:[3] 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.
The name of the genus comes from the Greek word ptilidion for "small feather", in reference to the multiply deeply divided leaves with fringed edges, which give the plant a "feathery" appearance. Unlike other leafy liverworts, the underleaves are not significantly smaller than the lateral leaves.[4] The "flossy" appearance from the leaf edges, together with the characteristic yellowish-brown or reddish-brown color make the genus easy to recognize.[5]
Like Ptilidium, Blepharostoma and Trichocolea have deeply divided leaves with marginal cilia, however Ptilidium differs from these other two genera in that its leaf cells have bulging trigones (thickenings at the corners between cell walls).[6]
The plants grow in dense mats, with stems growing either prostrate or ascending. Individual stems are once or twice pinnate, rarely with branches and only a few short rhizoids. The leaves are incubous and divided deeply into three to five portions, and edges of the leaf divisions are fringed with cilia. The underleaves are similar to the lateral leaves, but are slightly smaller. All species are dioicous, producing antheridia and archegonia on separate plants. The archegonia are terminal on a main stem. Mature sporophytes develop from within a large perianth with three distal folds.[7]
The three species in the genus may be distinguished by the density of cilia along the leaf margin, depth of lobing in the leaf, width of the leaf base, and the substrate on which it is found growing. P. californicum has few cilia along the edge of its leaves and has underleaves lobed to about seven-eighths of their length. The other two species have many marginal cilia and underleaves lobed to no more than half their length. P. ciliare usually grows on soil and has leaf lobes that are 15–20 cells wide at their base. P. pulcherrimum usually grows on wood or rock, and has leaf lobes normally 6–10 cells wide at their base.[6]
The genus Ptilidium has a boreal distribution, and is found in abundance in coniferous forests of Europe, Asia, and North America,[8] as well as in New Zealand[9] and Tierra del Fuego.[10] Plants often grow attached to the bark of trees in the northern hemisphere, but may occur in rocks in mountain districts of New Zealand. At the more temperate ends of its range, plants are restricted to higher elevations.[3]
Schuster (1984) proposed that the disjunct distribution of Ptilidium ciliare between the northern and southern hemispheres could be explained by migration of the Indian Plate from Gondwana.[11] In this hypothesis, P. ciliare is a species originally native to Gondwana, and sterile populations existing in modern New Zealand and Tierra del Fuego are relicts of this earlier distribution. The other two species of Ptilidium are thus believed to be later descendants. Schuster's hypothesis is partially based upon a belief that Ptilidium is related to the genera Mastigophora and Dendromastigophora, both of which are largely restricted to the southern hemisphere. However, this relationship is not supported by modern molecular analysis, which places Mastigophora in an entirely different part of the liverwort phylogeny.[12] Instead, Ptilidium is now believed to be part of an isolated clade allied only to two East Asian endemics, and it is thus more likely that the sterile populations of Ptilidium in the southern hemisphere reflect long-distance dispersal of plant fragments. Ptilidium ciliare is tolerant of desiccation and is ubiquitous in the Arctic, but rarely produces spores, and it is therefore believed to spread by means of such fragments.[11]
Leafy II (2600 spp)
Ptilidium
Leafy I (1800 spp)
The diagram at left summarizes a portion of a 2006 cladistic analysis of liverworts based upon three chloroplast genes, one nuclear gene, and one mitochondrial gene.[12][13] The genus Trichocoleopsis was not included in the original broad analysis, but is the sister taxon of Neotrichocolea according to a more narrowly focussed study utilizing six chloroplast genes, two nuclear genes, and a mitochondrial gene.[14]
The genus Ptilidium is sister to the Trichocoleopsis-Neotrichocolea clade. This combined clade, in turn, attaches at the base of a large clade (2600 species) designated "Leafy II". That clade, together with "Leafy I" (another 1800 species) and Pleurozia constitute the Jungermanniales, as traditionally defined. Ptilidium, Neotrichocolea, and Trichocoleopsis thus sit at the base of the Jungermanniales, at a point where the two major groups of leafy liverworts diverge from each other.
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.
Ptilidium es un género de hepáticas, y el único género en la familia Ptilidiaceae. Contiene solo tres especies:[3] Ptilidium californicum, Ptilidium ciliare, y Ptilidium pulcherrimum. El género se distribuye por toda la región ártica y subártica, con poblaciones separadas en Nueva Zelanda y Tierra del Fuego. El análisis molecular sugiere que el género tiene pocos parientes cercanos y se separaron temprano de otras hojas hepáticas en su evolución.
El nombre del género proviene de la palabra griega ptilidion de "pequeña pluma", en referencia a la multiplicación de las hojas profundamente divididas con flecos, que dan a la planta un aspecto "plumoso". A diferencia de otros hepáticas de hoja , las hojas inferiores no son significativamente más pequeñas que las hojas laterales.[4] El aspecto "sedoso" de los bordes de la hoja, junto con el color marrón amarillento o rojizo-marrón característico del género las hacen fácil de reconocer.[5]
Al igual que Ptilidium, Blepharostoma y Trichocolea tienen divididas profundamente las hojas con cilios marginales, sin embargo Ptilidium difiere de estos otros dos géneros en que las células de sus hojas tienen abultamiento trígonos (engrosamientos en las esquinas entre las paredes celulares ).[6]
Las plantas crecen en matas densas, con tallos que crecen, bien postrados o ascendentes. Los tallos individuales son una o dos veces pinnados , rara vez con ramas y sólo unos pocos cortos rizoides. Las hojas son incubous y divididas profundamente en cuatro y cincuenta y siete porciones, y los bordes de las divisiones de las hojas son flecos con los cilios. Las hojas inferiores son similares a las hojas laterales, pero ligeramente más pequeñas. Todas las especies son dioicas, produciendo anteridios y arquegonios en plantas separadas. Los arquegonios son terminales en un tallo principal. Los esporófitos maduros se desarrollan a partir de un gran perianto con tres dobleces distales.[7]
Frondosa II (2600 spp)
Ptilidium
Frondosa I (1800 spp)
El diagrama de la izquierda resume una parte de un análisis cladísticos de las hepáticas de 2006 sobre la base de tres genes de los cloroplastos, un gen nuclear, y un gen mitocondrial.[8][9] El género Trichocoleopsis no se incluyó en el análisis original, más amplio, pero es la hermana taxón de Neotrichocolea de acuerdo con un estudio más estrecho centrado la utilización de seis genes de los cloroplastos, dos genes nucleares, y un gen mitocondrial.[10]
El género Ptilidium es hermano del clado Trichocoleopsis - Neotrichocolea. Este clado combinado, a su vez, se une a la base de un gran clado (2600 especies) designado "frondosa II". Este clado, junto con "Frondosa I" (otros 1.800 especies) y Pleurozia constituyen el orden Jungermanniales, como tradicionalmente se define. Ptilidium , Neotrichocolea y Trichocoleopsis así se sientan en la base de los Jungermanniales, en un punto donde los dos grandes grupos de hepáticas divergen el uno del otro.
Ptilidiaceae fue descrita por Hugo Erich Meyer von Klinggräff y publicado en Die Höheren Cryptogamen Preussens 37. 1858.[11]
|coautores= (ayuda) |coautores= (ayuda) Ptilidium es un género de hepáticas, y el único género en la familia Ptilidiaceae. Contiene solo tres especies: Ptilidium californicum, Ptilidium ciliare, y Ptilidium pulcherrimum. El género se distribuye por toda la región ártica y subártica, con poblaciones separadas en Nueva Zelanda y Tierra del Fuego. El análisis molecular sugiere que el género tiene pocos parientes cercanos y se separaron temprano de otras hojas hepáticas en su evolución.
Narmik (Ptilidium) on narmikuliste sugukonda kuuluv helviksammaltaimede perekond.
Selles perekonnas on kolm liiki. Lisaks kahele Euroopas (sealhulgas Eestis) leiduvale kuulub siia Põhja-Ameerikas kasvav Ptilidium californicum.
Eestis leidub kaks selle perekonna liiki:
Narmik (Ptilidium) on narmikuliste sugukonda kuuluv helviksammaltaimede perekond.
Selles perekonnas on kolm liiki. Lisaks kahele Euroopas (sealhulgas Eestis) leiduvale kuulub siia Põhja-Ameerikas kasvav Ptilidium californicum.
Korallisammalet (Ptilidium) on aitomaksasammaliin kuuluva suku. Siihen kuuluu 2 Suomessa esiintyvää lajia.
Korallisammalet (Ptilidium) on aitomaksasammaliin kuuluva suku. Siihen kuuluu 2 Suomessa esiintyvää lajia.
Ptilidium là một chi rêu tản, và là chi duy nhất trong họ Ptilidiaceae. Chi này gồm ba loài:[3] Ptilidium californicum, Ptilidium ciliare, và Ptilidium pulcherrimum. Chúng phân bố khắp vùng cực và cận cực, với những quần thể riêng rẽ ở New Zealand và Tierra del Fuego. Phân tích phân tử cho thấy chúng có ít họ hàng gần và tách ra khá sớm khỏi phần còn lại của bộ Jungermanniales.
Bài viết liên quan đến bộ rêu Jungermanniales này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn.
Ptilidium là một chi rêu tản, và là chi duy nhất trong họ Ptilidiaceae. Chi này gồm ba loài: Ptilidium californicum, Ptilidium ciliare, và Ptilidium pulcherrimum. Chúng phân bố khắp vùng cực và cận cực, với những quần thể riêng rẽ ở New Zealand và Tierra del Fuego. Phân tích phân tử cho thấy chúng có ít họ hàng gần và tách ra khá sớm khỏi phần còn lại của bộ Jungermanniales.
손꼴가시이끼속 또는 털잎이끼속(Ptilidium)은 손꼴가시이끼목에 속하는 우산이끼류 속의 하나이다.[3] 손꼴가시이끼과(Ptilidiaceae)의 유일속으로 3종으로 이루어져 있다.
