Betula utilis 19th century, Kashmiri pandits reported all of their books were written on Himalayan birch bark until Akbar introduced paper in the 16th century. The Sanskrit word for the tree is "bhûrja"—sharing a similarity with other Indo-European words that provide the origin for the common name "birch". The bark is still used for writing sacred mantras, which are placed in an amulet and worn around the neck for protection or blessing. This practice was mentioned as early as the 8th or 9th century CE, in the Lakshmi Tantra, a Pancaratra text. According to legend, the bark was also used as clothing
Northern rough-winged swallow Northern rough-winged swallow The northern rough-winged swallow ("Stelgidopteryx serripennis") is a small, migratory swallow. It is very similar to the southern rough-winged swallow, "Stelgidopteryx ruficollis". The genus name, "Stelgidopteryx", is from Ancient Greek and means "scraper wing" and the species name, "serripennis", is derived from Latin and means "saw feather". In the common name, "rough-winged" refers to the serrated edge feathers on the wing of this bird; this feature would only be apparent when holding this bird. Six subspecies of the northern rough-winged swallow are currently recognized. It has been proposed that another race be recognized, "aphracta", but this is