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Huia (plant)
''Huia'' is a genus of extinct vascular plants of the Early Devonian (Pragian or Siegenian, around ). The genus was first described in 1985 based on fossil specimens from the Posongchong Formation, Wenshan district, Yunnan, China.
==Description==
The sporophyte of ''H. recurvata'' consisted of leafless stems (axes), branching both dichotomously and pseudomonopodially (i.e. with unequal divisions creating a 'main stem'). The sporangia (spore-forming organs) were born in terminal spikes on fertile stems, with the sporangia spirally arranged on stalks which curved downwards. The central strand of vascular tissue contained G-type tracheids. It was initially provisionally assigned to the "rhyniophytes". However, this group is defined as having terminal sporangia, whereas those of ''Huia'' are lateral, suggesting affinity with the zosterophylls.〔
A second species, ''H. gracilis'', was described from the Xujiachong Formation (Pragian–early Emsian), Qujing district, Yunnan, China. It differs from ''H. recurvata'' in its more slender morphology and its lack of pseudomonopodial branching. The adaxial sporangia, which were oval or elongated oval in shape, split (dehisced) along their length at right angles to the stem. It is suggested that ''Huia'' may have originated from early ''Cooksonia''-like plants.〔 Others suggest that its position is uncertain.〔, p. 249〕
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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