|
''Bommeria'' is a genus of small pteridaceous rock ferns, native to the New World. Genetic analysis has shown it to be a stem offshoot clade of all the cheilanthoid ferns (in family Pteridaceae),〔 except for ''Doryopteris'', which is an even more basal ("primitive") stem offshoot. for years, it was assumed that this genus was closely allied with ''Hemionitis'', but genetic analysis has shown that genus to be a more advanced genus evolutionarily. The same set of analysis has shown many presumed genera within this family to be paraphyletic, but the small genus ''Bommeria'' appears to be monophyletic, or a natural genus. ''Bommeria'' is a "gymnogrammoid" fern, exhibiting unprotected sori aligned along veins on the undersides of the fronds. This is why it was assumed to be closely allied to ''Hemionitis''. Such a feature is strongly at odds with most pteridoid ferns (Pteridaceae), which typically have linear marginal sori with an indusium, and sometimes protected with a reflexed leaf tissue margin. Apparently, this is a trait that can arise independently, and may be an atavistic trait. The stipes (leaf stems) of ''Bommeria'' are hairy, with some scales, and the fronds are hairy, both above and below. The hairs above and short and sharp, while the hairs below may be straight or curled. Scales are also present on the bottoms of the fronds. The genus name honors Belgian botanist Jean-Édouard Bommer. The basal chromosome number for this genus is ''2n=60'' (''n=30''). ==Species== *''Bommeria brandegeei'' (D.C. Eaton) - not yet assigned to ''Bommeria'', but proper placement according to Windham ''et al.'' 2009. *''Bommeria ehrenbergiana'' (Kl.) Underw. -- Mexico (same as ''Bommeria podophylla'' Fourn.) *''Bommeria elegans'' (Davenp.) Ranker & Haufler -- Mexico *''Bommeria hispida'' (Mett. ex Kuhn) Underw. -- copper fern, Mexico, Arizona, New Mexico, Texas (same as ''Bommeria schaffneri'' Fourn.) *''Bommeria knoblochii'' Maxon -- mountains of western Chihuahua, Mexico *''Bommeria pedata'' Fourn. -- western Mexico and Central America *''Bommeria subpalacea'' Maxon -- Mexico 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Bommeria」の詳細全文を読む スポンサード リンク
|