Mexican Upland Cotton Gossypium hirsutum – Native Plant of the Week

Introduction

Gossypium hirsutum has large and beautiful pale-yellow flowers and seeds covered in white cotton. It is both a beautiful and useful plant. The flowers are typical Malvaceae-type flowers with large overlapping petals and a staminal column in the center. It is native to Mexico and possibly southern Florida as well as the West Indies, Central America and northern South America. While it grows throughout the southern USA it is not native in most of it. Mexico is considered to be the center of origin and genetic diversity for Gossypium hirsutum where it was domesticated at least as far back as 3500 BC according to archeological evidence. This species of cotton accounts for about 90% of the worldwide cotton production and about 95% of the cotton production in the Americas.

Description of Upland Cotton Gossypium hirsutum

Stem & Leaves

Herbaceous short-lived perennial or annual from a taproot. It grows 1-2 m tall with widely-branching cylindrical stems that are covered with stellate (star-like) hairs.

Leaves are shallowly 3-5 lobed and 4-10 cm wide and they may be hairy or glabrous. They have a cordate (heart-shaped) base and an acute to acuminate (pointed) tip. Leaves grow on a long cylindrical petiole (leaf stalk) that is about 1/2 to the same length as the leaf itself. Leaves also possess stipules, small leaf-like appendages located at the base of the leaves, that are 5-15(-20) mm long.

Flowers & Fruits

The showy cream to yellowish flowers are 2-5 cm across and may or may not possess a red spot in the center of the flowers at the base of the petals. Flowers have small sepals 5-6 mm long with a truncate or 5-toothed tip.

The reproductive organs are contained in a 15 mm long staminal column characteristic of the Malvaceae family. The staminal column contains both the male and female reproductive organs in a single structure. It encloses the style and 3 to 5 stigmas that protrude past the male reproductive organs. The stamens are arranged around the column itself, located below the stigmas.

Its fruit is a 3 to 5 chambered ovoid or sub-globulose capsule that is 2-4 cm long and smooth and hairless. It contains 8-10 mmm seeds covered with white hairs (cotton).

Similar Species Frequently Confused With

Gossypium hirsutum does not have much for unrelated look-alikes due to its showy Malvaceae type flower and its unique fruits covered in white cotton. Occasionally, however, Hibiscus tiliaceus or Maritime Hibiscus is confused with it. Like Upland Cotton, it is also a member of the Malvaceae family and has large showy flowers but it grows as a tree and its flowers are much more yellow and contain a black spot rather than a red spot in the center. It is found in the southern states near the ocean and throughout much of Mexico.

We have many native Gossypium species that it could be confused with, but these all only grow in subtropical and tropical Americas. They can be differentiated as follows:

• Gossypium darwinii is a narrow endemic confined to the Galapagos with similar flowers but much more deeply lobed leaves. It is easily differentiated by its narrow range.
• Gossypium barbadense also known as Pima Cotton is found more in western South America but also grows in Florida, Hawaii, Mexico and the West Indies. It grows as a perennial rather than an annual but is very sensitive to cold so will only grow in subtropical to tropical areas. Its flowers are similar but generally a brighter yellow and the center spot may be red or blackish in color. The seeds are black instead of white.
• Gossypium herbaceum the African Cotton is rare in North America but is found in southern Florida as well as some locations in Mexico. It grows as a perennial to similar heights with similar flowers but its color ranges from white to yellow to pinkish and the spots in the center are purple instead of red. Its leaves are very wide and maybe entire to deeply lobed.
• Gossypium harknessii is a rare narrow endemic of the Baja peninsula of western Mexico. It is endangered globally. It is a perennial plant with thick glossy green heart-shaped leaves and grows in desert areas. Its flowers are similar but more bright yellow with petals that have wavy edges and very noticeable bright red dots at their bases in the center of the flower.

Distribution of Upland Cotton Gossypium hirsutum

Upland Cotton is native to Mexican, West Indies, Central America and northern South America. It is possibly also native to southern Florida. It has been introduced around the world for cotton production.

In Canada the climate is not suitable for Upland Cotton and it is not currently found there.

In the USA, Upland Cotton is found in California, Texas, Louisiana, Mississippi, Alabama, Florida, Missouri, Illinois, South Carolina, North Carolina, Virginia, Maryland, New Jersey, Pennsylvania and Massachusetts as well as Hawaii.

Gossypium hirsutum is found throughout all of Mexico but is most prevalent in the southern subtropical zone and less common in the northern desert areas.

Habitat & Growing Conditions of Mexican Cotton Gossypium hirsutum

Upland Cotton is found growing in full sun to partial shade in well-drained soils. While it prefers a moderate amount of moisture it will grow in areas prone to drought, in part due to its taproot that penetrates the soil in search of water. It will not grow well in permanently wet areas.

Growing Mexican Cotton in Your Garden

Make sure that the chosen location in your garden is similar to what it grows in its natural environment. Mexican Cotton is an easy plant to grow that tolerates a variety of conditions as long as certain parameters are met. Any area in full sun with well-drained soil will work perfectly. Commercial crops are generally grown in flat areas in well-drained soil and are often rain-fed for their water unless the area is a heavy drought zone in which case they are irrigated occasionally.

The biggest challenge to growing it in your garden is your climate since it is a subtropical and tropical species. However, it can be grown as an annual in more temperate climates.

Propagation is done by seeds that have a high germination and success rate. Some people use clonal propagation but this is generally not practical for the home gardener, especially with the high success rate of seed propagation.

Wildlife Values of Gossypium hirsutum

Native bees and butterflies routinely visit the flowers and the extrafloral nectaries. Birds frequently use the cotton bolls to build their nests. Seeds are rich in oil and are eaten by various birds and wildlife.

Status of Gossypium hirsutum

Mexican Cotton is considered Apparently Secure, G4 according to NatureServe. The IUCN Red List assessed it as globally Vulnerable in 2017.

Gossypium hirsutum does not grow in Canada.

In the USA Gossypium hirsutum is considered Vulnerable S3 in Florida. It is unranked in Massachusetts but should be listed as Exotic as it did not grow there before humans introduced it. In all other states where it is found it is listed as Exotic.

Gossypium hirsutum is found throughout Mexico, however, Mexico does not currently rank the status of native species on a state-by-state basis. The IUCN Red List has it listed as Globally Vulnerable so one could assume that in Mexico where it is native to it is considered a Vulnerable species in the wild.

Traditional or Other Uses of Upland Cotton

Gossypium hirsutum Medicinal Uses

Koasati peoples used a decoction of the roots to aid in childbirth.

Mexican Cotton Other Uses

Zuni people used the fibers to make ceremonial clothing and ceremonial cordage, particularly in masks and crowns associated with rainmaker ceremonies. They also tied the cotton cords around the wrists and ankles of newborns while making offerings so that the rainmakers would supply enough rain for the child to have a rich and full life. Cotton down was also used by the Zuni people in funeral proceedings for priests to symbolize their duties in this world and the other world.

Pima people used the seeds as a food source.

Gossypium hirsutum is a lovely short-lived perennial or annual plant that produces abundant flowers and lovely cottony fruits so it is occasionally grown as an ornamental in suitable climates.

Ethical Wildcrafting of Gossypium hirsutum

In North America, it is vulnerable in Florida which is the only state it is native in, so any wild plants seen in other states are escaped cultivars and can be harvested. It is, however, considered vulnerable globally so wild harvesting is not recommended. Instead, grow it in your garden for both its lovely leaves and flowers as well as its useful properties.

If you do harvest Gossypium hirsutum from the wild as always use the 1 in 20 rule of Ethical Wildcrafting. Pick one in every 20 mature fruits that you see.

Wildcrafting and Processing

Picked fruits can be placed in a basket, bowl, or paper bag and brought home for processing.

Generally speaking you should wait to pick the fruits until they are already dry and fully mature. If you harvest in the morning or shortly after a rain you should dry them before putting into storage. To dry the fruits simply place them on a rack or screen in a single layer and allow them to dry. Once dried the cotton bolls can easily be plucked from the seeds. Once dried they can be stored in a jar or bag for later use.

References and Resources

Canadensys Plant Search https://data.canadensys.net/vascan/search

Dictionary of Botanical Terms – by Lyrae’s Nature Blog https://lyraenatureblog.com/blog/dictionary-of-botanical-terms/

Eflora.org on Gossypium hirsutum http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200013695

iNaturalist Plant Search https://www.inaturalist.org/home

IUCN Red List https://www.iucnredlist.org/

Native American Ethnobotany http://naeb.brit.org/

Natureserve Explorer https://explorer.natureserve.org/Search

USDA Plants Database https://plants.sc.egov.usda.gov/home

Willis, Lyrae (Not Yet Published).  Plant Families of North America. 

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