Summer squash are squashes that are harvested when immature, while the rind is still tender and edible. Nearly all summer squashes are varieties of Cucurbita pepo, though not all Cucurbita pepo are considered summer squashes. Most summer squash have a bushy growth habit, unlike the rambling vines of many winter squashes. The name "summer squash" refers to the short storage life of these squashes, unlike that of winter squashes.
Summer squashes include:
In the journals of Lewis and Clark, on October 12, 1804, Clark recorded that the Arikara tribe raised "great quantities of Corn Beens Simmins, &c." Clark also used the spelling simlin in his journal entries. Simlin, variously spelled simblin, symnel, cymling, cimnel (Thomas Jefferson's spelling) and simnel were words for summer squash, particularly Cucurbita pepo ssp. pepo, common name pattypan squash. The word simnel was used because of the visual similarity between the squash and the simnel cake.