蓮子，是睡蓮(lian)(lian)科水生草(cao)本植物蓮(lian)(lian)的種子。又稱蓮(lian)(lian)實、蓮(lian)(lian)米(mi)、蓮(lian)(lian)肉(rou)，具有補脾止瀉，止帶，益腎澀精，養心安神之功效，常用于脾虛泄瀉，帶下，遺精，心悸失眠。蓮(lian)(lian)(lian)子(zi)以湘蓮(lian)(lian)(lian)為優(you)，湘蓮(lian)(lian)(lian)歷來作為進貢(gong)朝廷(ting)的珍品，故又稱(cheng)“貢(gong)蓮(lian)(lian)(lian)”。蓮(lian)(lian)(lian)子(zi)包括(kuo)紅蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)、白蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)、石(shi)蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)三種。石(shi)蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)是(shi)指成熟(shu)甚至陷于淤泥的蓮(lian)(lian)(lian)(lian)蓬(peng)剝(bo)下來或自然(ran)掉下來的帶(dai)(dai)黑色(se)外(wai)種皮的蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)。紅(hong)蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)是(shi)指除(chu)去(qu)外(wai)種皮的蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)，一(yi)般分(fen)為去(qu)芯(xin)和(he)不(bu)去(qu)芯(xin)兩種，白蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)是(shi)指去(qu)掉內種皮的蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)，也(ye)分(fen)去(qu)芯(xin)不(bu)去(qu)芯(xin)兩種。幾種蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)功效基本(ben)相(xiang)同(tong)但使用(yong)(yong)上略有區別：紅(hong)蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)帶(dai)(dai)紅(hong)色(se)外(wai)皮，一(yi)般用(yong)(yong)于養(yang)心安神(shen)的比(bi)較多(duo)，白蓮(lian)(lian)(lian)(lian)子(zi)(zi)(zi)色(se)白，一(yi)般用(yong)(yong)于潤肺健脾的多(duo)。

蓮(lian)子的(de)(de)質(zhi)(zhi)(zhi)量以湘蓮(lian)品(pin)質(zhi)(zhi)(zhi)最(zui)好。其皮(pi)色(se)淡紅，皮(pi)紋細(xi)致，粒大(da)飽滿，生吃(chi)微甜(tian)，一(yi)煮就酥，食之(zhi)軟糯清香。紅蓮(lian)質(zhi)(zhi)(zhi)量較差(cha)，其粒形(xing)瘦(shou)長(chang)，皮(pi)色(se)暗(an)花，臍部下陷，中心空間(jian)較大(da)，生吃(chi)味淡，久煮不酥。有的(de)(de)蓮(lian)子看起來又(you)白又(you)干凈(jing)，實(shi)際(ji)這種蓮(lian)子很有可能使用了對人體有害的(de)(de)化學漂白劑，而(er)且這些(xie)物質(zhi)(zhi)(zhi)會對肝臟造成傷害，引起重金屬中毒。真正優質(zhi)(zhi)(zhi)的(de)(de)蓮(lian)子，去皮(pi)后外表仍會有一(yi)點皺皮(pi)或未處(chu)理干(gan)凈(jing)的(de)(de)紅皮，劣質的(de)(de)則在刀(dao)口處(chu)有突起。蓮子經水(shui)蒸會(hui)發生膨(peng)脹，散發出(chu)一種清(qing)香，而添加了(le)化學制劑的(de)(de)蓮子幾乎不膨(peng)脹，還(huan)會(hui)有一種堿味。