Petunia is a genus of 20 species of flowering plants of South American origin. The popular flower of the same name derived its epithet from the French, which took the word , 'tobacco', from a Tupi–Guarani language. A tender perennial plant, most of the varieties seen in gardens are hybrids (Petunia × atkinsiana, also known as Petunia × hybrida).
Taxonomy
Petunia is a genus in the family Solanaceae, subfamily Petunioideae. Well known members of Solanaceae in other subfamilies include tobacco (subfamily Nicotianoideae), and the cape gooseberry, tomato, potato, deadly nightshade and peppers (subfamily Solanoideae). Some botanists place the plants of the genus Calibrachoa in the genus Petunia, Petchoa is a hybrid genus derived from crossing Calibrachoa and Petunia.
Species
Species include:
Ecology
Petunias are generally insect pollinated, with the exception of P. exserta, which is a rare, red-flowered, hummingbird-pollinated species. Most petunias are diploid with 14 chromosomes and are interfertile with other petunia species, as well as with Calibrachoa.
The tubular flowers are favoured by some Lepidoptera species, including the Hummingbird hawk moth.
Cultivation
Petunias can tolerate relatively harsh conditions and hot climates, but not frost. They need at least five hours of sunlight every day and flourish in moist soil and conditions of low atmospheric humidity. They are best grown from seed. Watering once a week should be sufficient in most regions. Hanging baskets and other containers need more frequent watering. Maximum growth occurs in late spring. Applying fertilizer monthly or weekly, depending on the variety, will help the plant grow quickly.
AGM cultivars
The following is a selection of cultivars which have received the Royal Horticultural Society's Award of Garden Merit:
- = 'Conblue'
- = 'Conglow'
- = 'Constraw'
- = 'Kleph15313'
- 'Storm Lavender'
- 'Storm Pink'
- 'Storm Salmon'
- = 'Suntosol'
- = 'Sunpurple'
- = 'Kerpril'
Uses
Many species other than Petunia × atkinsiana are also gaining popularity in the home garden. A wide range of flower colours, sizes, and plant architectures are available in both Petunia × atkinsiana and other species.
Genetically engineered bioluminescent Petunia hybrida was approved for sales by USDA in 2023. Called 'Firefly', this white-flowered petunia glows due to inserted genes from a bioluminescent mushroom.
Symbolism and folklore
The Maya and Inca believed that the scent of petunias had the power to ward off underworld monsters and spirits. Their flower-buds were bunched together for magical drinks.
Gallery
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File:Petunia Flowers (2).jpg|Red and white mixed petunia
File:Petunia Violet.jpg|Purple petunias with a white border
File:Petunia axillaris-Purple Petunia.JPG|A form of Petunia axillaris with a light pink flower
File:Petunia axillaris-White Petunia.JPG|White Petunia axillaris
File:Petunia red.jpg|A red petunia with a white border
File:Petunia Hybrid Bi Color.jpg|A cultivated form of petunia
File:Niz dvorot od Rašo 2013- 16 maj (107).JPG|Leaves of Petunia × atkinsiana
File:Petunia.jpg|A cultivated form
File:Starry night petunia flower in Porto Alegre - Brazil.jpg|Starry Night, found in Porto Alegre - Brazil.
File:Petunia Pink Sky.jpg|Pink Sky Petunia
File:Black petunia. II.jpg|Black Petunia
File:Petunia flower growing in Boothbay Maine 2024.jpg|Petunia flowers found growing in Boothbay, Maine
File:Field of Pink Petunia.jpg|Pink Petunia in Holambra - Brazil
File:Petunia x hybrida.JPG|Petunia x hybrida
File:African Sunset petunias.jpg|alt=|African Sunset, an orange petunia created with genetic modification
File:Petunia double petals.jpg|Petunia double petals
File:Petunia blue double petals.jpg|Petunia blue double petals
File:Firefly petunia.jpg|"Firefly" petunia, genetically engineered to produce a glow
File:Carmine Red Petunia 01.jpg|Carmine Red Petunia
File:Petúnias (do tupi petyma) de diferentes cores 01.jpg|Petunia axillaris
</gallery>