Cushaw crop origins (C. argyrosperma) a new encyclopedic overview

[markwkidd]

Why am I posting this:

• I would be grateful for any kind of feedback: things missing, correcting errors, etc.
• Also, I would be interested in chatting about the content. I find that reading some of these archeology and genetic taxonomy text really sparks my imagination and gets me excited about growing cushaws again this year.

2025 will be the first year that C. argyrosperma cushaw seeds are offered by GTS, and as the cushaw seed steward, this thread and writing project are part of my efforts to understand and promote the crop.

I took note a couple of years ago that the Wikipedia article for cushaws was only a “start-class” article. I made a few preliminary changes at the time and started gathering references for more comprehensive work.

I’m hoping that what I’ve created is enough starting point that a potential cushaw grower could learn the essential information from the fields of botany as well as history history. The idea with Wikipedia is also that the text doesn’t get too technical for a layperson to be able to understand.

Cucurbita argyrosperma

Cucurbita argyrosperma, commonly known as cushaw, kershaw, or silver-seed gourd, is a species of squash most grown most frequently in North and Central America, and believed to originate from southern Mexico. This annual herbaceous plant is cultivated in the for its nutritional value: its flowers, shoots, and fruits are all harvested, but it is cultivated commonly in its native range for seeds.

The species is believed to have originated in Mexico, from its wild sororia form. The reference genome of this species was published in 2019. In precolonial America, archaeological remains have been found as far northward as the Eastern Agricultural Complex. The extant native range of the wild sororia type is from northern Mexico through Central America to Nicaragua, at elevations from sea level to 1,900m.

The species epiphet “argyrosperma” means “silver seeds” in reference to the distinctively-colored seed margins of certain varieties. Cucurbita argyrosperma was formerly known as C. mixta. Historically, some varieties now recognized as C. argyrosperma were assigned to Cucurbita moschata instead. A small number of true C. moschata varieties are still commonly known as cushaws.

Description

The flowers are orange or yellow and bloom in July or August. The plant grows about 1 foot high and spreads 10–15 feet. It likes well drained soil and has both male and female flowers. Fruits can weigh up to 20 pounds.

A interspecific hybridization experiment in 1990 noted that as of that time Cucurbita argyrosperma was often grown in close proximity to Cucurbita moschata in Guatemala and Mexico. An interspecific variety called Chay Im’um in Mayan has been known to feature the seed quantity of Cucurbita moschata with the larger seed size of C. argyrosperma.

Systematics

Some authorities have used the name Cucurbita mixta for this species, but argyrosperma has been shown to have precedence. Prior to the modern understanding of this species, many C. argyrosperma varieties were assigned to the species Cucurbita moschata. Genetic research shows that C. argyrosperma and C. moschata are closely related but distinct.

Cucurbita argyrosperma

• subsp. sororia
• subsp. argyrosperma
  • var. argyrosperma
  • var. callicarpa
  • var. palmeri
  • var. stenosperma

Origin and History

The genus Cucurbita is endemic to the Americas, where it was more widely distributed in prehistoric times. Ecological shifts and the extinction of megafauna likely explain substantial reduction in wild Cucurbita populations during the Holocene epoch. The first example of a Curcubita species in cultivation is C. pepo which is believed to have been cultivated by inhabitants of Guilá Naquitz cave between 10,000 to 8,000 years ago.

Wild types

C. argyrosperma subspecies sororia is believed to be the wild ancestor of the other forms. The other free-living type, palmeri is placed in the domesticated subspecies C. argyrosperma subspecies argyrosperma variety palmeri. Variety ‘palmeri’ is believed to be a feral lineage that incorporates wild and domesticated genetics.

Both C. argyrosperma subsp. sororia and C. argyrosperma subsp. argyrosperma var palmieri are found in regions where domesticated C. argyrosperma has been grown for the longest time. Today the wild sororia type can be found growing freely from Nicaragua to Guatemala and the Mexican coasts of Veracruz, Chiapas, Oaxaca, Guerrero, Michoacán, Colima, Jalisco, Nayarit, Sinaloa, and Sonora. It was formally described by Liberty Hyde Bailey in 1943, in Gentes Herbarum. Sororia, meaning ‘sister’, was historically classified as closely related to Cucurbita texana with which it hybridizes well. In 1948, the proposed type for another species Cucurbita kellyana was published, but this taxa is now considered a synonym for sororia. The palmieri type is found from the Pacific coast of northwestern Mexico to Nicaragua. It was originally formally described by Liberty Hyde Bailey in 1943, in Gentes Herbarum and is now believed to be a mixture of wild and domesticated genetics.

Domestication

The earliest known possible archaeological records of C. argyrosperma are 8,700-year-old phytoliths in the Central Balsas River valley in Guerrero, but these remains are considered ambiguous. The earliest unambiguous specimen is a C. argyrosperma peduncle that has been dated to approximately 5,100 years ago, from the Ocampo caves.

Genetic evidence centers the domestication of C. argyrosperma in what is now Jalisco, Mexico. Other evidence suggests that following domestication and before European contact, C. argyrosperma diffused northward into what is now the eastern and central United States before European contact. C. argyrosperma seeds have been recovered from Late Mississippian archaeological contexts in Arkansas that suggest domesticated C. argyrosperma was established in that region 1,310–623 years ago.

Domestication involved genetic changes to attributes related to growing, handling, and using the plant. C. argyrosperma is thought to follow a domestication pattern similar to other Cucurbita, beginning with reduction of bitterness and an increase in seed size. In C. argyrosperma, attributes affected by domestication and selective breeding include:

• reduction in bitter taste from cucurbitacins
• increase in the size of fruits and seeds
• more uniform germination time
• reduced size and abundance of urticating trichomes (hair)
• diversification of fruit shape

Variety argyrosperma of Cucurbita argyrosperma subsp. argyrosperma has historically been cultivated in eastern and southern Mexico Mexico and in Central America. The geographic center of cultivation for variety callicarpa has been central and northwestern Mexico and the southwestern United States. This variety has been documented in Argentina and Peru where it is believed to be a relatively recent introduction. Subspecies argyrosperma var. stenosperma is endemic to Mexico and has historically been cultivated in the region south of Mexico City.

Some evidence suggests that the modern subsp. argyrosperma var. argyrospermа most closely resembles early domesticated C. argyrosperma. In southern Mexico and Guatemala, var. stenosperma and var. argyrosperma are cultivated for seeds. The fruit often used as animal feed. Common names for these types, pipiana and pepitoria, reflects of their selection for seeds.

The diversity of fruit and seed morphology in var. stenospermа and callicarpa suggest selection has occurred for the fruit’s flesh as well as for edible seeds in those varieties. Further south, the immature fruits of var. stenosperma are consumed as a “summer squash” vegetable. There farmers often grow landrace varieties which have diverse attributes in many regards but prioritize long-necked fruits. Fruits with a long neck are considered preferable when the flesh is used for culinary purposes.

Variety callicarpa is found the farthest north of the domesticated varieties. It also typically features elongated rather than globose fruit. In general, the flesh var. callicarpa is considered of higher culinary quality than the fruit of var. stenosperma and var. argyrosperma.

Eastern North America

One issue facing assessments of the origins and history of domesticated Cucurbita argyrosperma relates to the fact that that the species was not fully described at the time of many archaeological studies guided the 20th century understanding of the domestication and dispersal of this species. Ancient peduncle remains may have been mistakenly assigned to C. maxima and C. moschata, while seed remains may have been assigned to C. maxima, C. moschata, or C. pepo.

Domesticated landraces of C. argyrosperma subsp. argyrosperma var callicarpa may have reached what is now Virginia and New England hundreds of years before European colonization.

Cultivars

In areas where C. argrosperma is traditionally cultivated, it is common to use term to describe fruit based on its qualities rather than using a cultivar name. Only a few named cultivars of Cucurbita argyrosperma have been commercialized. Cultivars in commercial distribution in the United States are usually var. callicarpa, and include ‘Green Striped Cushaw’, ‘Orange Striped Cushaw’, ‘Jonathan Pumpkin’, ‘White Cushaw’, ‘Japanese Pie’, and ‘Tennessee Sweet Potato’.

Commercial cultivars that have been selected from var. argyrosperma include ‘Silverseed Gourd’ and ‘Campeche Squash’.

[markwkidd]

A version of this text is live on Wikipedia at Cucurbita argyrosperma - Wikipedia

That’s where you can view the bibliography and there is some more content in the full article about uses. The Wikipedia version places footnotes next to the text so it’s easier to see which reference is used for what information if someone would like to know more about the sources I’ve been using.

[DebbieA]

Nice work, Mark. Do all the varieties look similar to each other? I was wondering if the different varieties are easy to distinguish. Also, are cushaws ever used ceremonially, or only as food and medicine?

In the photo ‘Calabaza rayada’ for sale in Tucumán, Argentina’, are the cushaws the ones right in front of the man? The ones on the left side of the photo look like a moschata I grew last year.

I noticed some typos. If you’d like me to point them out, do you have a document I can mark up?

[markwkidd]

I’m very grateful for your review on my work. I apologize I have been slow getting back to you. I’m going to write one reply focused on some Wikipedia volunteer processes, then I will write something separate about cushaw classification.

I’ve been affected by several waves of destructive weather. Also, just after I shared these updates here, I experienced a copyright review on the C. argyrosperma text I contributed. It was the combo of these two events that slowed me down. I was very stressed about the copyright review, it being my first, but in the end, it only resulted in minor changes: Cucurbita argyrosperma: Difference between revisions - Wikipedia

The main contention seems to be that the long list of common names I included was worded closely to the text of one of my sources. If I want to include those names, I just need to find an additional source and use different phrasing. So for now, that part remains absent.

Facts are not copyrightable, but it’s important to respect that some arrangements or presentations of factual information may be protectable. If anyone is interested in digging into copyright law and the “sweat of the brow” doctrine about factual information and copyright: Copyright law of the United States - Wikipedia

One of my intentions with this thread is to help popularize Wikipedia, although I didn’t expect I would be getting corrected by a more senior editor, that’s part of the process there. This kind of review is very rare, and even though it worried and felt a little embarrassing, I’m reassured that only minor, technical changes were requested. I contributed large amounts of new writing and big contributions should be given scrutiny.

Edited for clarity

[markwkidd]

Edits/correction

Thanks again for reviewing my work. I hadn’t thought about how to collaborate on the text. If you still have the corrections you mentioned, would you consider editing Wikipedia directly? This is the same URL you would get from pressing the edit button on the article: Cucurbita argyrosperma - Wikipedia

An account is not required for making that kind of change. If that doesn’t seem good, I would be very glad to set up a Google Doc and work together there.

Argentina market photo

@DebbieA thank you for pointing out the fruits on the left of the photo from the market in Argentina. Those peduncles are not corky, and flare where they meet the fruit. That photo and some of the others are used in the Spanish language article on C. argyrosperma. I brought it over the English article but I hadn’t looked closely enough.

I removed the photo in question. I would not add a photo with that type of peduncle to the C. argyrosperma article unless a good authority was adamant it was argyrosperma.

A thought about the encyclopedias in other languages. As you may infer, article translation is done by human editors and its not unusual for articles to have very different content from one language to another. I forget to check other languages. For the plant and agriculture topics I am working on Spanish and German wikipedia are often useful, but there can be good stuff in other languages too.

Botanical varieties and systematics for cushaw

I am very interested in a better description for the botanical types that you ask about. And a key. I have read several papers that provide clues for how to differentiate between them, but nothing that is created as a resource to aid in classification. I got some hands on training from some local old timers in my area, which helps complement all the reading I’ve done even though I think all the local ones are one botanical variety: callicarpa.

I still have a way to go and I don’t truly understand the distinctions yet.

I’ll try to share my in-progress understanding. The three domesticated varieties are all included in subspecies argyrosperma:

• subsp. argyrosperma var argyrosperma
• subsp. argyrosperma var stenosperma
• subsp. argyrosperma var callicarpa

var argyrosperma

Round and oblong shapes. Maybe pyriform. Not likely to have neck or take other shapes like club or flattened pumpkin. These most closely resemble cushaws from early archeological remains.
Often bred for seeds. Seeds are often among the largest of Cucurbita. Seeds often have a blue, green, or gray margin per the epithet “argyrosperma” but I’m not sure this attribute is diagnostic
This is may be most commonly grown in the west and south of Mexico?

var stenosperma

May be round, oblong, pyriform, or necked. Not likely to take other shapes like club or flattened pumpkin.
The epithet means “narrow seeds” but I’m not sure that narrow seeds are diagnostic.
Often bred for seeds? Often bred for summer squash? May be used as winter squash less frequently?
This may be most frequently found in South and Southeastern Mexico?

var callicarpa

May be round, oblong, pyriform, or necked. Most commonly grown for pyriform and necked types
The epithet translates into beautiful fruit
Traditionally grown for winter squash with secondary use for summer squash or edible seeds.
Traditionally grown from northern Mexico through the southeastern United States

[DebbieA]

@markwkidd

If you still have the corrections you mentioned, would you consider editing Wikipedia directly?

I made some very minor corrections to the text directly in Wikipedia. Thank you for suggesting that. It was very straightforward, and it was good to be able to review the changes before publishing. Is there a way to make corrections without publishing so that another collaborator can review the changes first?

[markwkidd]

Thanks for making the edits!

I forgot to respond to your question about ceremonial uses. I have not come cross much information about that yet. I hope that I can find some additional sources from ethnobotany and anthropology.

I will suggest that you take a look at one source I have been using, because it has a detailed photo of an early sculpture that seems to portray C. argyrosperma. It also goes into some detail about species ID and peduncle, which we’ve also been discussing: Precolumbian Cucurbita argyrosperma ssp. argyrosperma (Cucurbitaceae) in the Eastern Woodlands of North America

The article was published in 1994 during a wave of reassessment of species ID and genetic relationships. I would love to know if Dr. Fritz would change anything in this article based on newer information.

At any rate, Fritz believes argyrosperma is plausible for this scuplture, and if so, that helps with the ancient timeline of the crop as well as its cultural significance.

The Birger Figurine

This remarkable work of art came from an unusual precinct that evidently served as a ritual facility at approximately A.D. 1100 (Bareis and Porter 1984; Emerson and Jackson 1984). Much has been written about the Birger Figurine (Emerson 1982, 1989; Emerson and Jackson 1984; Prentice 1986) and the symbolism it embodies. Researchers seem to be in agreement that fertility is symbolized by the female figure kneeling and hoeing the back of a serpent whose body bifurcates and becomes a squash or gourd vine that climbs up her back.

Six fruits are attached to the divided vine. They are approximately as long as the figure's upper arm and pyriform in shape, with markedly-to-slightly constricted neck or shoulder areas occupying the upper one-third of each fruit

[markwkidd]

About collaborating on articles and sharing drafts on Wikipedia. All articles and some other types of pages have a tab or button which takes you to its twinned “Talk Page”

There is also a Talk Page for your own user account.

The Talk Page is like a combination of a scratch pad and a message board. It’s kind of primitive, so active talk pages tend to start looking like a big sprawling google doc as years go on.

This is a short overview of the functionality here: Help:Introduction to talk pages/All - Wikipedia

As that article mentions, there often won’t be any editors proactively monitoring a talk page, so it may be necessary to invite other editors or tag them.

The Wikipedia site doesn’t try to gently push people towards collaboration as much as other platforms (like github or even google docs). There is an attitude of: if you’re not positive about an edit, but you’re acting in good faith, go ahead and make the edit.

To be transparent, I am hardly active at all in the community of Wikipedia editors. It’s very different than the way I participate here. I mostly keep in alignment with the norms there by reading other editors work and reviewing their changes. Otherwise I keep to myself and only work on articles I’m interested in, rarely corresponding with other editors.

My low-contact way of working there isn’t the only way, but I think there are many others like me that only rarely collaborate on an article at the same time.