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''Hillebrandia sandwicensis'' is a species of a herbaceous perennial flowering plant native to some of the Hawaiian Islands. Common names include aka aka awa〔(【引用サイトリンク】University of California, Berkeley">url=http://calphotos.berkeley.edu/cgi/img_query?stat=BROWSE&query_src=photos_flora_sci&where-genre=Plant&where-taxon=Hillebrandia+sandwicensis&title_tag=Hillebrandia+sandwicensis )〕 and pua maka nui. The genus name honors the German physician William Hillebrand. In terms of morphology, ''H. sandwicensis'' is similar to ''Begonia'', but differences in flower structure, pollen morphology, and fruit differentiate the two genera.〔 It produces tubers, to which above–ground parts of the plant die back to after producing fruit in the summer. The seeds are very small. Plants regrow in January. It blooms from February to June.〔 It is monoecious, with succulent branches.〔 It is found in humid ravines covered with forest at altitudes of 900–1800 meters. Additionally, ''H. sandwicensis'' is the only member of its family natively found in the Hawaiian Islands.〔 It is classified in the family Begoniaceae and is the only species in the genus ''Hillebrandia''; indeed, it the only one of the 1400 or so species in the family Begoniaceae ''not'' to be a member of the genus ''Begonia''.〔 It is the sister taxon to the rest of its family. The time of the split is considerably older than the oldest above–water Hawaiian Island (Kure Atoll) by an appreciable period of time. This arises a bit of a mystery as to how a monotypic genus got to a remote island chain considerably younger than itself. It has been proposed that, even though forested ravines are not particularly windy, ''Hillebrandia'' island–hopped down the Hawaiian – Emperor seamount chain (then islands) via the wind often enough to colonize each island in turn, a process aided by a Cenozoic climate allowing it to live at lower altitudes than today, regardless of where the genus originated from.〔 ''Hillebrandia'' may also be younger than previous estimates.〔 ''H. sandwicensis'' is currently found only on the islands of Maui, Molokai, and Kauai. It is locally extinct on Oahu, and does not occur on the Big Island. Despite an abundance of suitable habitat, the species is localized and uncommon. It has recently been getting rarer,〔 but despite this, it is not (as of 2011) listed on the International Union for the Conservation of Nature's Red List.〔Using the (Red List website's search function ) yields no hits for the word "''Hillebrandia''"〕 However, a 1999 document from the American Fish and Wildlife Service did list ''H. sandwicensis'' as one of 202 "Other Species of Concern".〔 ==References== 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「Hillebrandia」の詳細全文を読む スポンサード リンク
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