Trees hold a particular role in Germanic paganism and Germanic mythology, both as individuals (sacred trees) and in groups (sacred groves). The central role of trees in Germanic religion is noted in the earliest written reports about the Germanic peoples, with the Roman historian Tacitus stating that Germanic cult practices took place exclusively in groves rather than temples. Scholars consider that reverence for and rites performed at individual trees are derived from the mythological role of the world tree, Yggdrasil; onomastic and some historical evidence also connects individual deities to both groves and individual trees. After Christianisation, trees continue to play a significant role in the folk beliefs of the Germanic peoples. Terminology The pagan Germanic peoples referred to holy places by a variety of terms and many of these terms variously referred to stones, groves, and temple structures. From Proto-Germanic , a masculine noun, developed Old Norse meaning 'temple, idol', Old English 'temple, idol', and Old High German meaning 'holy grove, holy stone'. According to philologist Vladimir Orel, the term was borrowed from the continental Celtic * or, alternately, the same non-Indo-European source as the Celtic source. A more general term for a sacred place was reflected in Old Norse vé. The Proto-Germanic masculine noun , which developed into Old Frankish ('holy grove'), similarly either developed from, or is otherwise connected to, Gaulish , Latin and Old Irish 'holiness'. Another Proto-Germanic masculine noun , has given rise to words with a variety of meanings in various Germanic languages, including Anglo-Saxon , 'meadow', Middle Low German , 'bush', and Old High German , , 'grove, copse, bush'; it is cognate with Latin , 'sacred grove'. Scandinavian placenames occur with the name of a deity compounded with , 'grove', or , 'wood'. Attestations and archaeological record Sacred trees and groves are widely attested among the records of the ancient Germanic peoples. Some scholars hypothesize that they even predated the development of temples (according to Rudolf Simek, "there were sacred woods long before there were temples and altars"). In his Germania, Tacitus says that the Germanic peoples "consecrate woods and groves and they apply the name of gods to that mysterious presence which they see only with the eye of devotion", Tacitus describes the grove of the Semnones and refers to a castum nemus ('chaste grove') in which the image of the goddess Nerthus was hallowed, and other reports from the Roman