Kalmar "Cenchrus tribuloides" tana nufin nau'in ciyawa da aka fi sani da "bindweed", "chiggergrass", "burgrass", ko "sandburs". Wani nau'in ciyawa ne na shekara-shekara wanda ke haifar da kaifi, fashe-fashe wanda zai iya zama mai zafi don takawa ko taɓawa. Burs ɗin abin damuwa ne na kowa a cikin lawns da sauran wuraren waje, saboda suna iya mannewa cikin sauƙi ga sutura, Jawo, ko fata. Ita wannan shuka ta fito ne daga Arewacin Amurka kuma ana samun ta a cikin yashi ko ƙasa mai cike da damuwa.