Stretch Spiders are a family of Orbweb Spiders, also called Long-jawed Orbweb Spiders. This one is probably Tetragnatha montana (the Common Stretch Spider). Stretch spiders build simple orb webs, fairly near water. When disturbed they leave the web and stretch out their body and legs in a thin line along a leaf or stem which provides camouflage. It is this behaviour that gives them their common name.