The invention provides a polyester bicomponent staple fiber comprising poly(trimethylene terephthalate) and at least one polymer selected from the group consisting of poly(ethylene terephthalate), poly(trimethylene terephthalate), and poly(tetramethylene terephthalate) or a combination of such members, said bicomponent staple fiber having: a) a scalloped oval cross-section shape having an aspect ratio a:b of about 2:1 to about 5:1 wherein 'a' is a fiber cross-section major axis length and 'b' is a fiber cross- section minor axis length; b) a polymer interface substantially perpendicular to the major axis; c) a cross-section configuration selected from the group consisting of side-by- side and eccentric sheath-core; d) a plurality of longitudinal grooves; and e) a groove ratio of about 1.05:1 to about 1.9:1. Additionally, the invention provides a spun yarn comprising cotton and the polyester bicomponent staple fiber of the invention, as well as fabrics and garments comprising the spun yarn of the invention.