Horse
Besides the horse, there are six other species of genus "Equus" in the Equidae family. These are the ass or donkey, "Equus asinus"; the mountain zebra, "Equus zebra"; plains zebra, "Equus quagga"; Grévy's zebra, "Equus grevyi"; the kiang, "Equus kiang"; and the onager, "Equus hemionus".
Equisetopsida
Equisetopsida, or Sphenopsida, is a class of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. Living horsetails are represented by about twenty herbaceous species in the single genus "Equisetum". They typically grow in wet areas, with whorls of needle-like branches radiating at regular intervals from a single vertical stem.