阿里山天胡荽

阿里山天胡荽學名Hydrocotyle setulosa Hayata、Hydrocotyle laxiflora Masam.、Hydrocotyle masamunei M. Hiroe，英文名Setulose Pennywort，五加科天胡荽亞科天胡荽屬多年生草本植物，又稱刺毛天胡荽，原產於台灣，植株平臥，節上生根，莖匍匐，枝條密被短柔毛，嫩枝直立，單葉互生，葉圓腎形、心形，端部五至七淺裂，裂片寬淺鈍鋸齒，裂端闊圓形，鈍，彼此貼近，葉基心形，葉緣圓鋸齒、鈍鋸齒，葉長五至二十公釐，寬八至二十五公釐，葉面綠、深綠、翠綠色，葉表面密被細剛毛，背面被柔毛、長刺毛，放射狀羽狀脈，似掌狀，細脈網狀，托葉闊圓形，全緣或二裂，膜質，淡褐色，半透明狀，闊三角形，葉柄長約一至七 公分，密被向下反曲捲柔毛，兩性花，繖形花序，頭狀排列，腋生，叢生狀，花序單生，徑約四公釐，花序梗長二至十公分，常較葉柄長，密被向下反曲的柔毛，具多數花，約十五至三十枚，密集成頭狀，總梗綠色，絲狀，花梗短，長約一公釐，總苞片宿存，苞片綠白色，卵狀披針形，花萼合生筒狀，萼齒微小，萼片五枚，綠白色，卵狀三角形，長寬不足半公釐，與子房合生，花小形，花冠幅形、星形，輻射對稱，花徑約一公釐，花乳白、綠白色，早落，先端五裂(花瓣五枚)，裂齒微小或不明顯，長橢圓狀卵形，頂端銳形，通常內曲，早落，鑷合狀排列，雄蕊五枚，與花瓣互生，花藥淺褐色，丁字著生，二室，縱裂，雌蕊心皮二枚，合生，花柱二枚，圓柱形，長約不足半公釐，著生於花盤上，基部膨大，成花柱基，圓錐形或扁平，分泌花蜜，花柱宿存，子房綠色，扁球形，高與徑不足一公釐，厚不足半公釐，子房下位，子房一、二室，中軸胎座，或說基生胎座，每室具胚珠一枚，扁狀橢圓球形，離果，心形、圓球形，長約一公釐，寬約一至二公釐，綠、褐色，雙懸果，兩側扁壓，兩面有稜，果稜明顯，先端具宿存花柱，果瓣柄近無，長不足半公釐，分果片二枚，果熟分離，種子半圓形，扁平狀。

天胡荽(Hydrocotyle)屬原屬於繖形科，依APG II分類法移入五加科。

天胡荽(Hydrocotyle)屬常見之品種有：
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Hydrocotyle acutiloba
Hydrocotyle algida
Hydrocotyle asiatica(雷公根) 註：歸雷公根屬(Centella)
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Hydrocotyle batrachium(台灣天胡荽)
Hydrocotyle benguetensis(菲島天胡荽、呂宋天胡荽)
Hydrocotyle bonariensis(大葉銅錢草)
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Hydrocotyle calcicola(石山天胡荽)
Hydrocotyle callicarpa
Hydrocotyle changanensis(長安天胡荽)
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Hydrocotyle delicata(姬天胡荽)
Hydrocotyle dichondroides(毛天胡荽、毛柄天胡荽)
Hydrocotyle dichondroides var. dichondroides(毛天胡荽)
Hydrocotyle dichondroides var. tatunensis(大屯山天胡荽)
Hydrocotyle dielsiana(裂葉天胡荽)
Hydrocotyle dissecta
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Hydrocotyle foveolata
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Hydrocotyle geraniifolia
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Hydrocotyle heteromeria
Hydrocotyle himalaica(喜馬拉雅天胡荽)
Hydrocotyle hirta
Hydrocotyle hookeri(阿薩姆天胡荽)
Hydrocotyle hookeri subsp. chinensis(中華天胡荽)
Hydrocotyle hookeri subsp. handelii(普渡天胡荽)
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Hydrocotyle javanica(爪哇天胡荽)
Hydrocotyle javanica var. chinensis(中華胡荽、地彈花)
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Hydrocotyle keelungensis(基隆天胡荽)
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Hydrocotyle leucocephala(白頭天胡荽、金錢草、香香草)
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Hydrocotyle moschata
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Hydrocotyle nepalensis(乞食碗、紅馬蹄草)
Hydrocotyle novae-zelandiae
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Hydrocotyle pedicellosa(大雷公根)
Hydrocotyle peduncularis
Hydrocotyle peltiformis
Hydrocotyle podantha(柄花天胡荽)
Hydrocotyle prolifera
Hydrocotyle pseudoconferta(密繖天胡荽、密傘天胡荽)
Hydrocotyle pterocarpa
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Hydrocotyle ramiflora(長梗天胡荽)
Hydrocotyle ranunculifolia(毛茛葉天胡荽)
Hydrocotyle ranunculoides
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Hydrocotyle setulosa(阿里山天胡荽、刺毛天胡荽)
Hydrocotyle salwinica(怒江天胡荽)
Hydrocotyle sibthorpioides(天胡荽、南美天胡荽)
Hydrocotyle sibthorpioides var. batrachium
Hydrocotyle sibthorpioides var. sibthorpioides(原變種)
Hydrocotyle sibthorpioides var. tuberifera(基隆天胡荽)
Hydrocotyle sibthorpioides 'Crystal Confetti'
Hydrocotyle sibthorpioides 'Lawn Pennywort'
Hydrocotyle sibthorpioides 'Variegata'
Hydrocotyle sp. australia(澳洲天湖葵)
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Hydrocotyle trachycarpa
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Hydrocotyle umbellata(繖形天胡荽)
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Hydrocotyle verticillata(銅錢草、錢幣草、銅幣草、圓幣草、南美天胡荽)
Hydrocotyle vulgaris(野天胡荽、香菇草、盾葉天胡荽)
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Hydrocotyle wilfordii(腎葉天胡荽、惠氏天胡荽)
Hydrocotyle wilsonii(鄂西天胡荽)
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