Annual or short-lived perennial shrub to 2 m tall. Leaves ovate to lanceolate, up to 12 cm long but generally much smaller. Stalk 1-4 cm long. Flowers solitary, occasionally in pairs, white or green, to about 1.5 cm wide. Fruit to 15 cm or so long, yellow, orange, green, red, purple or black.
Unknown in the wild but probably from tropical America
var. glabriusculum (Dunal) Heiser & Pickersgill, Bird Pepper, has small bright orange-red fruits to 2.5 cm long and 0.5-1 cm wide and represents the wild or spontaneous forms that occur in America; it has naturalised in Darwin, NE NSW and E Qld, mostly on the fringes of rainforest.
C. frutescens L. from tropical America has small, red, narrow, conical to ellipsoid or fusiform fruits 3-6 mm wide, and is used for Tabasco and other hot sauces (although the name has sometimes been incorrectly applied to cultivars of C. annuum var. annuum). It is naturalised from NE NSW to E Qld.
C. annuum var. annuum is grown as a wide range of ornamental and culinary peppers in 5 major groups. Commercial plantations occur throughout the world's tropics and subtropics. Most recent breeding work has been performed by seed companies in Holland to meet supermarket demand for early yielding, disease-resistant, even-sized, thick-fleshed fruits in a range of colours. Australia has about 100 cultivars - too numerous to detail here (many are known under trademark names). Commercial production in Australia is in all states although the largest crops occur in Queensland in Burdekin and Bundaberg.
The five major groups are:
Cerasiforme Group - Cherry Peppers Fruit small, cherry-like in size but mostly yellow or purplish and extremely pungent.
Conoides Group - Cone Peppers Fruit mostly erect and conical.
Fasciculatum Group - Red Cone Peppers Fruit red, erect, slender, in clusters. Extremely pungent.
Grossum Group - Bell Pepper, Capsicum, Green Pepper, Red Pepper, Pimiento, Sweet Pepper Fruit large, thick-walled, irregularly shaped and indented at the base, not pungent to the taste. This group contains the mild yellow, green, orange, red and purple salad peppers.
Longum Group - Cayenne Pepper, Chilli Pepper Fruit pendulous and sometimes 20-30 cm long. These are the hot peppers, sources of cayenne pepper, chilli powder and paprika.
Selection of listed names: (Many of these may not be true cultivar names) 'Bell', 'Brown Beauty', 'California Wonder', 'California Wonder Yellow', 'Chinese Giant', 'Domino', 'Espadon', 'Fireworks', 'Fort Knox', 'Green Giant', 'Gypsy', 'Holiday Cheer', 'Holiday Time', 'Hungarian Yellow Wax', 'Inferno', 'Jackpot', 'Jalapeno', 'Lemon Beauty', 'Lilac Lady', 'Long Green', 'Long Green Cuban', 'Long Hot Cayenne', 'Long Hot Red', 'Long Hot Yellow', 'Long Red Cayenne Thick', 'Long Sweet Green', 'Long Sweet Yellow', 'Magnum', 'Masai', 'Mellow Yellow', 'Mexicana', 'Midas', 'Olympian', 'Orange Beauty', 'Purple Heart', 'Purple Princess', 'Pylon Red', 'Red Hot', 'Red Thin Cayenne', 'Rialto', 'Sergeant Pepper', 'Sultan', 'Sunray', 'Sweet Mix', 'Target', 'Treasure Red', 'Variegata', 'Volcano', 'Wildfire', 'Wonderbelle', 'Yellow Bell', 'Yolo Wonder'.
Source: (2002). Solanaceae. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.