纏繞草質(zhi)(zhi)藤(teng)本。塊莖長圓(yuan)(yuan)柱形(xing)(xing)(xing)(xing)，垂(chui)直生(sheng)(sheng)長，長可(ke)達1米(mi)多，斷面干(gan)時(shi)(shi)白色。莖通常帶紫(zi)(zi)紅色，右旋，無(wu)毛。單(dan)葉(xie)(xie)(xie)(xie)，在莖下部(bu)的互生(sheng)(sheng)，中部(bu)以上的對生(sheng)(sheng)，很(hen)少3葉(xie)(xie)(xie)(xie)輪(lun)生(sheng)(sheng)；葉(xie)(xie)(xie)(xie)片(pian)(pian)變(bian)異大，卵(luan)狀(zhuang)(zhuang)(zhuang)(zhuang)三(san)角形(xing)(xing)(xing)(xing)至(zhi)寬(kuan)卵(luan)形(xing)(xing)(xing)(xing)或戟形(xing)(xing)(xing)(xing)，長3-9 (-16) 厘(li)米(mi)，寬(kuan)2-7 (-14) 厘(li)米(mi)，頂端漸尖，基部(bu)深(shen)心(xin)形(xing)(xing)(xing)(xing)、寬(kuan)心(xin)形(xing)(xing)(xing)(xing)或近(jin)(jin)截形(xing)(xing)(xing)(xing)，邊緣(yuan)常3淺裂(lie)至(zhi)3深(shen)裂(lie)，中裂(lie)片(pian)(pian)卵(luan)狀(zhuang)(zhuang)(zhuang)(zhuang)橢圓(yuan)(yuan)形(xing)(xing)(xing)(xing)至(zhi)披針形(xing)(xing)(xing)(xing)，側裂(lie)片(pian)(pian)耳狀(zhuang)(zhuang)(zhuang)(zhuang)，圓(yuan)(yuan)形(xing)(xing)(xing)(xing)、近(jin)(jin)方形(xing)(xing)(xing)(xing)至(zhi)長圓(yuan)(yuan)形(xing)(xing)(xing)(xing)；幼苗時(shi)(shi)一般葉(xie)(xie)(xie)(xie)片(pian)(pian)為(wei)寬(kuan)卵(luan)形(xing)(xing)(xing)(xing)或卵(luan)圓(yuan)(yuan)形(xing)(xing)(xing)(xing)，基部(bu)深(shen)心(xin)形(xing)(xing)(xing)(xing)。葉(xie)(xie)(xie)(xie)腋(ye)內(nei)常有珠芽。雌(ci)雄(xiong)異株。雄(xiong)花(hua)(hua)序(xu)為(wei)穗狀(zhuang)(zhuang)(zhuang)(zhuang)花(hua)(hua)序(xu)，長2-8厘(li)米(mi)，近(jin)(jin)直立，2-8個著(zhu)生(sheng)(sheng)于(yu)葉(xie)(xie)(xie)(xie)腋(ye)，偶而呈圓(yuan)(yuan)錐(zhui)狀(zhuang)(zhuang)(zhuang)(zhuang)排列；花(hua)(hua)序(xu)軸(zhou)明顯地呈“之”字(zi)狀(zhuang)(zhuang)(zhuang)(zhuang)曲折(zhe)；苞片(pian)(pian)和花(hua)(hua)被(bei)片(pian)(pian)有紫(zi)(zi)褐(he)色斑點；雄(xiong)花(hua)(hua)的外輪(lun)花(hua)(hua)被(bei)片(pian)(pian)為(wei)寬(kuan)卵(luan)形(xing)(xing)(xing)(xing)，內(nei)輪(lun)卵(luan)形(xing)(xing)(xing)(xing)，較小；雄(xiong)蕊6。雌(ci)花(hua)(hua)序(xu)為(wei)穗狀(zhuang)(zhuang)(zhuang)(zhuang)花(hua)(hua)序(xu)，1-3個著(zhu)生(sheng)(sheng)于(yu)葉(xie)(xie)(xie)(xie)腋(ye)。蒴果不反折(zhe)，三(san)棱(leng)狀(zhuang)(zhuang)(zhuang)(zhuang)扁圓(yuan)(yuan)形(xing)(xing)(xing)(xing)或三(san)棱(leng)狀(zhuang)(zhuang)(zhuang)(zhuang)圓(yuan)(yuan)形(xing)(xing)(xing)(xing)，長1.2-2厘(li)米(mi)，寬(kuan)1.5-3厘(li)米(mi)，外面有白粉；種子著(zhu)生(sheng)(sheng)于(yu)每室(shi)中軸(zhou)中部(bu)，四(si)周有膜質(zhi)(zhi)翅。花(hua)(hua)期6-9月，果期7-11月。