浮水(shui)草本,高30-60厘米(mi)。須根發達(da),棕(zong)黑色,長(chang)(chang)達(da)30厘米(mi)。莖(jing)極短,具(ju)長(chang)(chang)匍匐枝,匍匐枝淡綠(lv)色或帶紫(zi)色,與母(mu)株(zhu)分(fen)離后長(chang)(chang)成新植(zhi)物。
葉(xie)(xie)在(zai)基部叢生,蓮座狀(zhuang)(zhuang)排列,一般(ban)5-10片(pian);葉(xie)(xie)片(pian)圓形(xing)(xing),寬(kuan)卵形(xing)(xing)或寬(kuan)菱形(xing)(xing),長4.5-14.5厘(li)米(mi),寬(kuan)5-14厘(li)米(mi),頂(ding)端鈍圓或微尖,基部寬(kuan)楔(xie)形(xing)(xing)或在(zai)幼時為淺心形(xing)(xing),全(quan)緣,具弧形(xing)(xing)脈,表面深綠色(se),光亮,質地厚實,兩邊微向上卷,頂(ding)部略向下翻卷;葉(xie)(xie)柄長短不等,中部膨大(da)成囊狀(zhuang)(zhuang)或紡(fang)錘形(xing)(xing),內有許多多邊形(xing)(xing)柱(zhu)狀(zhuang)(zhuang)細胞組成的氣室,維管束散布其間,黃綠色(se)至綠色(se),光滑;葉(xie)(xie)柄基部有鞘狀(zhuang)(zhuang)苞片(pian),長8-11厘(li)米(mi),黃綠色(se),薄而半(ban)透明;
花(hua)(hua)(hua)(hua)葶從葉柄基(ji)(ji)部(bu)(bu)(bu)的(de)鞘狀苞(bao)片(pian)(pian)腋內伸出(chu)(chu),長(chang)(chang)34-46厘(li)(li)(li)米(mi)(mi)(mi),多(duo)棱(leng);穗(sui)狀花(hua)(hua)(hua)(hua)序長(chang)(chang)17-20厘(li)(li)(li)米(mi)(mi)(mi),通常具9-12朵花(hua)(hua)(hua)(hua);花(hua)(hua)(hua)(hua)被(bei)(bei)裂(lie)片(pian)(pian)6枚,花(hua)(hua)(hua)(hua)瓣狀,卵(luan)(luan)形(xing)(xing)、長(chang)(chang)圓形(xing)(xing)或倒卵(luan)(luan)形(xing)(xing),紫(zi)藍(lan)(lan)色(se),花(hua)(hua)(hua)(hua)冠略(lve)兩側(ce)對(dui)稱,直(zhi)徑4-6厘(li)(li)(li)米(mi)(mi)(mi),上方(fang)1枚裂(lie)片(pian)(pian)較(jiao)大,長(chang)(chang)約(yue)3.5厘(li)(li)(li)米(mi)(mi)(mi),寬(kuan)(kuan)約(yue)2.4厘(li)(li)(li)米(mi)(mi)(mi),三色(se)即四周淡紫(zi)紅色(se),中(zhong)間藍(lan)(lan)色(se),在藍(lan)(lan)色(se)的(de)中(zhong)央有(you)(you)1黃色(se)圓斑,其余(yu)各片(pian)(pian)長(chang)(chang)約(yue)3厘(li)(li)(li)米(mi)(mi)(mi),寬(kuan)(kuan)1.5-1.8厘(li)(li)(li)米(mi)(mi)(mi),下方(fang)1枚裂(lie)片(pian)(pian)較(jiao)狹(xia),寬(kuan)(kuan)1.2-1.5厘(li)(li)(li)米(mi)(mi)(mi),花(hua)(hua)(hua)(hua)被(bei)(bei)片(pian)(pian)基(ji)(ji)部(bu)(bu)(bu)合生(sheng)(sheng)成(cheng)筒(tong),外面近(jin)基(ji)(ji)部(bu)(bu)(bu)有(you)(you)腺(xian)(xian)毛;雄(xiong)蕊6枚,貼生(sheng)(sheng)于花(hua)(hua)(hua)(hua)被(bei)(bei)筒(tong)上,3長(chang)(chang)3短,長(chang)(chang)的(de)從花(hua)(hua)(hua)(hua)被(bei)(bei)筒(tong)喉(hou)部(bu)(bu)(bu)伸出(chu)(chu),長(chang)(chang)1.6-2厘(li)(li)(li)米(mi)(mi)(mi),短的(de)生(sheng)(sheng)于近(jin)喉(hou)部(bu)(bu)(bu),長(chang)(chang)3-5毫(hao)米(mi)(mi)(mi);花(hua)(hua)(hua)(hua)絲上有(you)(you)腺(xian)(xian)毛,長(chang)(chang)約(yue)0.5毫(hao)米(mi)(mi)(mi),3(2-4)細胞,頂端(duan)膨大;花(hua)(hua)(hua)(hua)藥箭形(xing)(xing),基(ji)(ji)著,藍(lan)(lan)灰色(se),2室(shi),縱裂(lie);花(hua)(hua)(hua)(hua)粉(fen)粒長(chang)(chang)卵(luan)(luan)圓形(xing)(xing),黃色(se);子房(fang)上位,長(chang)(chang)梨形(xing)(xing),長(chang)(chang)6毫(hao)米(mi)(mi)(mi),3室(shi),中(zhong)軸胎(tai)座,胚珠多(duo)數;花(hua)(hua)(hua)(hua)柱(zhu)1,長(chang)(chang)約(yue)2厘(li)(li)(li)米(mi)(mi)(mi),伸出(chu)(chu)花(hua)(hua)(hua)(hua)被(bei)(bei)筒(tong)的(de)部(bu)(bu)(bu)分有(you)(you)腺(xian)(xian)毛;柱(zhu)頭上密(mi)生(sheng)(sheng)腺(xian)(xian)毛。蒴果卵(luan)(luan)形(xing)(xing)。花(hua)(hua)(hua)(hua)期7-10月(yue),果期8-11月(yue)。
原產(chan)巴西。廣布于中(zhong)國長(chang)江、黃河流域及華南各省。生于海(hai)拔(ba)200-1500米(mi)的水塘、溝渠及稻田(tian)中(zhong)。亞洲(zhou)熱帶地區(qu)也已廣泛生長(chang)。
選擇開(kai)花(hua)植株較多的(de)(de)(de)(de)水塘(tang),不(bu)打撈,于(yu)9-10月(yue),待小(xiao)果呈淡黃(huang)時(shi),將彎曲(qu)的(de)(de)(de)(de)結果花(hua)梗(geng)摘下,采后(hou)攤暗風干,剝(bo)去(qu)果皮,取出(chu)種(zhong)(zhong)(zhong)子。若(ruo)于(yu)盛花(hua)時(shi)的(de)(de)(de)(de)上午(wu)9-10點(dian),將露出(chu)花(hua)粉的(de)(de)(de)(de)花(hua)在(zai)拄頭(tou)上擦觸幾下,可(ke)壘部(bu)結實,種(zhong)(zhong)(zhong)子飽滿(man)。品(pin)種(zhong)(zhong)(zhong)優良。2月(yue)下旬至(zhi)3月(yue)初將飽滿(man)且呈黃(huang)褐色的(de)(de)(de)(de)種(zhong)(zhong)(zhong)子放在(zai)25-30℃水中浸種(zhong)(zhong)(zhong)10天,然后(hou)播在(zai)水面(mian)上,井(jing)保持3O℃左右的(de)(de)(de)(de)溫度和濕(shi)度狀態,經1至(zhi)2周萌(meng)發。待幼苗長出(chu)5-6片葉時(shi),葉捅開(kai)始蟛大,已有(you)一定浮(fu)力,幼苗分枝后(hou)即可(ke)移植。立夏以后(hou),平均(jun)氣溫升至(zhi)20℃左右,可(ke)移至(zhi)內塘(tang)的(de)(de)(de)(de)水面(mian)養殖。
鳳(feng)眼藍(lan)腋芽(ya)較多,能(neng)(neng)發育戚為(wei)新(xin)的(de)植株,匍匐枝(zhi)較長,嫩脆易斷,斷離(li)后(hou)亦成(cheng)為(wei)獨立的(de)新(xin)株,具(ju)有(you)租強的(de)無性(xing)繁(fan)殖能(neng)(neng)力(li)。