Greening - Tree Labels with QR Codes (114)

Scientific Name : Carica papaya L.
Common Name : Papaya
Chinese Name : 番木瓜
Family : CARICACEAE
Local distribution status : Exotic species

Anecdotes on plants

Origin	Understanding the origins of domesticated crops can open avenues for investigating evolution and human history. However, the paucity of wild and archaeological samples and extremely complicated hybridization events always beleaguer the relative studies. Then, can scientists disentangle these problems? Papaya perhaps is a proper example to elaborate. The origin of Papaya has been argued for ages due to a dearth of direct archaeological evidence. 'Southern Mexico to Central America as the origins of Papaya' is currently the most accepted assumption. You may wonder, if there is no fossil record, how can scientists confidently support the assumption? Before, we should first understand the reproductive biology of Papaya. Plant sex expression is mainly regulated by hormones and sex chromosomes. To our knowledge, Papaya's sex expression is controlled by three types of a pair of sex chromosomes: female (XX), male (XY) and hermaphrodite (XY^h). The Y chromosome is vital for male expression and the genetic mutation of which can shift the male to hermaphrodite. Today, hermaphroditic Papaya is pervasively growing in farmlands. However, when we glimpse into the past, the ancient population of Papaya was actually dominated by distinct males and females, while hermaphrodite was more likely a freak. Supported by the recent molecular data, a divergence between the populations of male and hermaphroditic Papaya probably showed at around 4000 years ago, a time which serendipitously congruent to the rise of the Maya civilization. Coupled with other indirect information, including the high phylogenetic linkage of Papaya to the plants which are endemic to Mexico, and greater genetic diversity of Papaya showing in Mexico, we can roughly draw a picture as follows: the origin of Papaya was in Mesoamerica, particularly Mexico. Before domestication, the population of hermaphroditic Papaya was rare. Until the Mayan, probably at 4000 years ago, they spotted the advantages of hermaphroditic Papaya and further started the voyage of Papaya to be one of the well-known fruits in the world.
Meanings of name	The generic name Carica refers to Caria that was confused to be the origin of Papaya. The specific epithet papaya is derived from the Carib Indian name ababai.
Application	Papaya is one of the most cultivated crops in the world. The fleshy and wholesome fruits are the abundant sources of vitamins A, B and C, and other micronutrients such as calcium and iron. The fruit can be eaten fresh or processed into soup with meat by virtue of the white latex that contains a protein-digesting enzyme 'papain' to tenderize meat.

Origin

Understanding the origins of domesticated crops can open avenues for investigating evolution and human history. However, the paucity of wild and archaeological samples and extremely complicated hybridization events always beleaguer the relative studies. Then, can scientists disentangle these problems? Papaya perhaps is a proper example to elaborate.

The origin of Papaya has been argued for ages due to a dearth of direct archaeological evidence. 'Southern Mexico to Central America as the origins of Papaya' is currently the most accepted assumption. You may wonder, if there is no fossil record, how can scientists confidently support the assumption? Before, we should first understand the reproductive biology of Papaya. Plant sex expression is mainly regulated by hormones and sex chromosomes. To our knowledge, Papaya's sex expression is controlled by three types of a pair of sex chromosomes: female (XX), male (XY) and hermaphrodite (XY^h). The Y chromosome is vital for male expression and the genetic mutation of which can shift the male to hermaphrodite. Today, hermaphroditic Papaya is pervasively growing in farmlands. However, when we glimpse into the past, the ancient population of Papaya was actually dominated by distinct males and females, while hermaphrodite was more likely a freak.

Supported by the recent molecular data, a divergence between the populations of male and hermaphroditic Papaya probably showed at around 4000 years ago, a time which serendipitously congruent to the rise of the Maya civilization. Coupled with other indirect information, including the high phylogenetic linkage of Papaya to the plants which are endemic to Mexico, and greater genetic diversity of Papaya showing in Mexico, we can roughly draw a picture as follows: the origin of Papaya was in Mesoamerica, particularly Mexico. Before domestication, the population of hermaphroditic Papaya was rare. Until the Mayan, probably at 4000 years ago, they spotted the advantages of hermaphroditic Papaya and further started the voyage of Papaya to be one of the well-known fruits in the world.

Meanings of name

The generic name Carica refers to Caria that was confused to be the origin of Papaya. The specific epithet papaya is derived from the Carib Indian name ababai.

Application

Papaya is one of the most cultivated crops in the world. The fleshy and wholesome fruits are the abundant sources of vitamins A, B and C, and other micronutrients such as calcium and iron. The fruit can be eaten fresh or processed into soup with meat by virtue of the white latex that contains a protein-digesting enzyme 'papain' to tenderize meat.

Traits for identification

Growing habit	Small evergreen tree.
Height	To 8 m tall.
Stems	Bark greyish white, smooth. Stem usually solitary, with conspicuous leaf scars, branched when injured, with white latex secretion.
Leaves	Petioles hollowed, long (to 1 m). Simple leaves alternate, clustered at the apex of stem. Blade suborbicular, glabrous, palmately and deeply 7-11 lobed, each lobe deeply and broadly toothed.
Flower	Flowers unisexual or bisexual. Male flowers sessile, clustered in a large panicle, pendulous, corolla tube creamy, stamens 10, in 2 whorls. Female flowers with short pedicel or sessile, solitary or aggregated in cymes, corolla tube very short, 5-lobed, ovary ovoid, stigma partite, nearly fimbriate, corolla tube creamy. Bisexual flowers clustered in short racemes, stamens 5 or 10.
Fruit	Berries obovoid or ellipsoid, large, heavy, turning green to orange-yellow when mature.
Seeds	Black, many, with fleshy aril.
Flowering period	January to December in Hong Kong.
Fruiting period	January to December in Hong Kong.

Remarks

Scientific names from other databases :
― Flora of China : Carica papaya Linnaeus
― Plant of the World Online : Carica papaya L.

Papaya

Anecdotes on plants

Traits for identification

Remarks

Reference