Five populations of a new dagger nematode species were recovered from natural grasslands and forests of north and northwest Iran, and described based upon morphological and molecular data in present paper. Xiphinema hyrcaniense n. sp. is characterized by 3.9–5.5 mm long females, having 102–142 μm long odontostyle, 64–88 μm long odontophore, guiding ring located at 115–147 μm distance from anterior end, two equally developed genital branches having crystalloids in tubular part of uteri and pseudo-Z-organ at their junction with pars dilatata uteri, short, rounded to dorsally more convex tail with a mucro or in few specimens, without it. Common males with 72–95 μm long spicules and four juvenile developmental stages. The new species is similar to six known species belonging to artificial morphospecies group 5, especially looking closest to X. montenegrinum in its general morphology, but could be separated by ontogenesis of tail shape and morphometric indices. In molecular phylogenetic analyses using partial large subunit, and internal transcribe spacer 1 ribosomal DNA (LSU D2-D3 and ITS1 rDNA) sequences, the new species formed a clade with X. cretense and Xiphinema sp. in LSU; and in ITS1 tree, with X. dentatum and X. paradentatum.

从伊朗北部和西北部的天然草地和森林中回收了五种新的匕线虫物种，并根据形态和分子数据对其进行了描述。剑线虫hyrcaniense ñ。sp。其特征是雌性长3.9-5.5mm，齿形长102-142μm，齿突长64-88μm，引导环位于距前端115-147μm的距离，两个同样发育的生殖器分支在子宫小管部分具有晶体和假Z型器官在与子宫parsata的交界处短，圆形，背面具粘膜或到一些标本，没有粘毛，到背面更凸的尾巴。具72-95μm长针刺和四个幼体发育阶段的普通雄性。该新物种类似于属于人工形态物种第5组的6个已知物种，特别是在一般形态上看起来最接近黑山黑麦草，但是可以通过尾部形状和形态计量指数的本体发生来分离。在使用部分大亚基和内部转录间隔区1核糖体DNA（LSU D2-D3和ITS1 rDNA）序列的分子系统发育分析中，新物种与X. cretense和Xiphinema sp形成了进化枝。在路易斯安那州立大学; 在ITS1树中，带有X. dentatum和X. paradentatum。