纏繞草質藤本。塊(kuai)莖長(chang)(chang)(chang)圓(yuan)(yuan)柱形(xing)(xing)，垂直(zhi)(zhi)生(sheng)長(chang)(chang)(chang)，長(chang)(chang)(chang)可達(da)1米(mi)多，斷面干時白色(se)。莖通常(chang)帶紫紅色(se)，右(you)旋(xuan)，無毛(mao)。單葉(xie)，在(zai)莖下部的互生(sheng)，中(zhong)部以上(shang)的對生(sheng)，很少3葉(xie)輪生(sheng)；葉(xie)片(pian)變異(yi)大(da)，卵(luan)(luan)(luan)狀(zhuang)三(san)角(jiao)形(xing)(xing)至(zhi)寬(kuan)卵(luan)(luan)(luan)形(xing)(xing)或戟(ji)形(xing)(xing)，長(chang)(chang)(chang)3-9 (-16) 厘(li)米(mi)，寬(kuan)2-7 (-14) 厘(li)米(mi)，頂端漸尖(jian)，基部深心形(xing)(xing)、寬(kuan)心形(xing)(xing)或近截形(xing)(xing)，邊緣常(chang)3淺裂至(zhi)3深裂，中(zhong)裂片(pian)卵(luan)(luan)(luan)狀(zhuang)橢圓(yuan)(yuan)形(xing)(xing)至(zhi)披針形(xing)(xing)，側裂片(pian)耳狀(zhuang)，圓(yuan)(yuan)形(xing)(xing)、近方形(xing)(xing)至(zhi)長(chang)(chang)(chang)圓(yuan)(yuan)形(xing)(xing)；幼苗時一般(ban)葉(xie)片(pian)為(wei)寬(kuan)卵(luan)(luan)(luan)形(xing)(xing)或卵(luan)(luan)(luan)圓(yuan)(yuan)形(xing)(xing)，基部深心形(xing)(xing)。葉(xie)腋(ye)內(nei)常(chang)有(you)珠芽。雌雄(xiong)(xiong)異(yi)株。雄(xiong)(xiong)花(hua)(hua)(hua)序(xu)(xu)為(wei)穗狀(zhuang)花(hua)(hua)(hua)序(xu)(xu)，長(chang)(chang)(chang)2-8厘(li)米(mi)，近直(zhi)(zhi)立，2-8個著生(sheng)于(yu)(yu)葉(xie)腋(ye)，偶而呈圓(yuan)(yuan)錐狀(zhuang)排列；花(hua)(hua)(hua)序(xu)(xu)軸明(ming)顯(xian)地呈“之”字狀(zhuang)曲折；苞片(pian)和(he)花(hua)(hua)(hua)被片(pian)有(you)紫褐(he)色(se)斑點；雄(xiong)(xiong)花(hua)(hua)(hua)的外(wai)輪花(hua)(hua)(hua)被片(pian)為(wei)寬(kuan)卵(luan)(luan)(luan)形(xing)(xing)，內(nei)輪卵(luan)(luan)(luan)形(xing)(xing)，較小；雄(xiong)(xiong)蕊6。雌花(hua)(hua)(hua)序(xu)(xu)為(wei)穗狀(zhuang)花(hua)(hua)(hua)序(xu)(xu)，1-3個著生(sheng)于(yu)(yu)葉(xie)腋(ye)。蒴(shuo)果(guo)不反折，三(san)棱(leng)狀(zhuang)扁圓(yuan)(yuan)形(xing)(xing)或三(san)棱(leng)狀(zhuang)圓(yuan)(yuan)形(xing)(xing)，長(chang)(chang)(chang)1.2-2厘(li)米(mi)，寬(kuan)1.5-3厘(li)米(mi)，外(wai)面有(you)白粉；種子著生(sheng)于(yu)(yu)每室(shi)中(zhong)軸中(zhong)部，四周有(you)膜質翅。花(hua)(hua)(hua)期6-9月，果(guo)期7-11月。