Domesticated and grown by Native Americans for thousands of years, squash and pumpkins are an indigenous crop of the Americas. (Photo credit: April O’Meara)
This article originally appeared in the Arizona Daily Sun on October 24th.
I love this time of year, seeing all the Halloween decorations made up of squashes, gourds and jack-o’-lanterns. Botanically, it makes me think of the cucurbit or gourd plant family formally called the Cucurbitaceae.
Consisting of over 950 wild species across 101 genera, the members of this family that have the most cultural, agricultural, commercial and nutritional value for humans include four domesticated species in the Cucurbita genus. Although the growing techniques for cucurbits in the garden such as winter squash, pumpkins, gourds and zucchini are essentially the same, let’s take a closer look at how these plants are grouped into different species by botanists.
Cucurbita argyrosperma is the species least commonly grown in home gardens today. However, genetic studies suggest that the species was domesticated by indigenous peoples in the central Balsas River Valley of southern Mexico and has been in continuous cultivation since 3100 BCE. The species includes most cashew squash types and silver-seeded gourds. Plants have particularly vigorous vines with large, rounded, shallowly-lobed leaves that produce smooth fruits. The species can also be differentiated from other squashes by its large pale seeds that are covered in a thin cellophane-like seed coat. Many varieties, such as ‘Silver Edged’, are grown specifically for their edible seeds.
Prized for their rich orange edible flesh, Cucurbita maxima was most likely domesticated from a wild squash in what is now Bolivia and Argentina. Archaeological evidence indicates Cucurbita maxima was being grown by native communities along the coast of Peru over 4,000 years ago. The species consists of a wide variety of winter squash such as the teardrop-shaped Hubbard squashes, flat-topped buttercups, turban, banana and mammoth varieties as well as Kuri and kabocha squashes so popular in Asian cuisine. Fruits vary widely in size, rind texture, shape, and color, including everything from Australian blue varieties, such as ‘Sibley’, to the near-white rind of ‘Hopi White’. Cucurbita maxima characteristically produces plants with kidney-shaped leaves, distinctive corky fruit stems at maturity, and thick seeds with narrow margins.
Most varieties of Cucurbita moschata are recognized by their tan, buff, or pale-orange rind. However, some exhibit spotted rinds while others are green tinted or bicolor. The species includes “necked” pumpkins such as ‘Canada Crookneck’, the more recently bred butternut cultivars that are a favorite of gardeners and grocery stores, and cheese pumpkins, aptly named for their flattened wheel-of-cheese like appearance. Plants typically exhibit leaf silvering which is described as white spots at the intersections of leaf veins, while their seeds have wrinkled margins and a pronounced seed scar.
Cucurbita moschata was first developed from wild cucurbits in the humid lowlands of southern Mexico at around 4900 BCE. Over the centuries, the rich flesh has provided a flavorful and storable source of carbohydrates, vitamins, and beta-carotene. Heirloom cultivar names, such as ‘Musquee de Provence, ‘Virginia Mammoth’, ‘Long of Naples’ and ‘Futtsu’, point to its cultivation in France, Italy, the United States, and Japan. One of my personal favorites of this species is the cultivar ‘Magdalena Big Cheese’ — traditionally grown with summer monsoons in Sonora, Mexico and southern Arizona.
Finally, the cucurbit that adorns most people’s dinner plates and decorates porches in the form of Halloween Jack-o’-lanterns, miniature pumpkins, and warted and scalloped gourds is Cucurbita pepo. This species is also comprised of summer squash, including zucchini, straightneck, crookneck, and patty pan (scallop) types, as well as certain winter types, including acorn, spaghetti, delicata, cocozelle, marrow, and dumpling squash. This huge diversity is due to the species being the first cucurbit known to have been domesticated throughout the Americas. In fact, seeds have been excavated in an Oaxaca, Mexico settlement site that date to over 10,000 years! This long history of cultivation has also made this species widely adaptable to a range of climates and growing conditions across the world.
If you would like to see hundreds of carved Cucurbita pepo jack-o’-lanterns on display, then come out to the Arboretum at Flagstaff this Saturday, October 26, from 4 to 8 p.m. for our annual Pumpkin Walk. The night will also feature food carts, hot beverages, craft beer, festive music and family-friendly activities. Costumes are encouraged! Tickets available at thearb.org.
Nate O’Meara is the Executive Director of The Arboretum at Flagstaff.
