Western hemlock often grows in the shade under Douglas fir. Favored substrates include hardwood mulches made of oak, eucalyptus, Douglas fir, and alder. Reaction on condensed tannins from Douglas fir bark produces epicatechin and catechin thioglycolates. Species of fir, Douglas fir, spruce and pine were represented. Vancouver Island is also the location where some of the tallest Douglas fir were recorded. The lances used are long, weighing about , made of Douglas fir. The roof includes 2,400 cubic metres of Douglas fir lamstock lumber in glulam beams. Open coniferous forests of Douglas fir and ponderosa pine dominate the slopes around Lytton. The dugout was long, made of Douglas fir, and weighed . The ship was built from Douglas fir and Virginia oak. In March 2008, the yellow pine mainmast was replaced with one of Douglas fir. Fir, also known as Douglas Fir, is very inexpensive and common at local home centers. Most impressive are the beams&colon; 100-foot-long bars of laminated Douglas fir, trucked from Canada. These spars are laminated usually from spruce or douglas fir (by clamping and glueing). It is named after the Douglas fir, featured on the flag.