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1991年4月份以来,我们先后在北京市朝阳区黑桥马路边和昌平县草碾开河岸边发现了二种苍耳,经鉴定为平滑苍耳和意大利苍耳。其中草碾开河岸一带发生面积较大。这二种苍耳在我国尚无记载,属于国内新发现的田间杂草。为了便于识别现将这二种苍耳,形态特征概述如下:1.平滑苍耳 Xanthium strumarium var.glabratum(D.C.)Crong为一年生草本植物,生育期5—10月,株高50—300cm,浓绿色。茎粗糙生有短毛,茎上具短线状的黑色斑,茎的一侧呈紫褐
Since April 1991, we have discovered two kinds of Xanthium flavescens in the grassy bank of Blackbridge Road and Changping County, Chaoyang District, Beijing. They were identified as Smooth Xanthium and Italian Xanthium. Among them, grass mulching open river bank area occurred larger. These two kinds of cocklebur in our country has no records, belong to the newly discovered field weeds. In order to facilitate the identification of these two kinds of cocklebur now, the morphological characteristics are summarized as follows: 1. Smooth Xanthium strumarium var.glabratum (DC) Crong is an annual herb with a growth period of 5-10 months and a plant height of 50-300cm, . Stems with rough short stems, stalks with short-shaped black spots, the side of the stem was purple brown