Family : Heliconiaceae
Text © Pietro Puccio
English translation by Mario Beltramini
The species is native to Belize, Colombia, Costa Rica, Ecuador, Guatemala, Honduras, Panama, Trinidad and Tobago and Venezuela, where it grows at the margins of the humid forests or along the water streams, from the sea level up to about 600 m of altitude.
The name of the genus comes from the Latin “Heliconius, a, um” = of the Helicon, mountain sacred to Apollo and to the Muses in the Greek mythology; the species is honoured to the German explorer, collector and naturalist Moritz Friedrich Wagner (1813-1887).
Common names: Easter heliconia (English); tracoà (Portuguese–Brazil); platanilla, platanillo (Spanish).
The Heliconia wagneriana Petersen (1896) is an evergreen, perennial, rhizomatous erect herbaceous species, forming dense 1,5-4,5 m tall tufts. The leaves, on a 30-90 cm long petiole, are basal, alternate, simple, entire, oblong with brusquely pointed apex and central nervation prominent in the lower page, slightly waved, 0,8-1,6 m long and 20-30 cm broad, of green colour, and sheathing tubular foliar bases forming a 1-1,5 m long flattened pseudo-stem.
The inflorescence is a sessile, up to about 45 cm long, erect spike, with 7-20, alternate, distichous, concave, waxy, pointed, overlapped at the base and wholly wrapping the rachis, bracts, of pinkish red colour edged of pale yellow and green margins, 13-15 cm long in the median part, progressively descending going upwards. The bracts subtend numerous tubular flowers curved towards the apex, 4-7 cm long, of intense green colour at the apex, white at the base, rich of nectar, opening in succession; the bracts secrete a liquid that gathers in the cavity, besides rain water, and which protects the reproductive organs from the herbivorous insects.
The flowers, with bilateral symmetry, are hermaphroditic, with three sepals, two of which merged and one free, and 3 petals fused together, little differentiated between them, 5 fertile stamina and one staminode opposite to the free sepal; the flowers are pollinated by the hummingbirds. The fruits, on a white pedicel, are oblong trigonal, 1,5 cm long drupes, blue when ripe, containing 1-3 wrinkly seeds, 1 cm long and 0,6 cm broad. It reproduces by seed, previously scarified and kept in water for 3 days to soften the tegument, in organic loam with addition of siliceous sand or agri-perlite for a 30%, maintained humid at the temperature of 26-28 °C, with germination times variable, from one to six months, micropropagation, but usually and easily by division of the rhizomes in spring, with each section provided with several vegetative buds, to be interred at a depth of no more than 3 cm.
Species of great ornamental and landscape effect, with the prolonged flowering with a maximum between late winter and early spring (short-day species), requires a humid tropical or subtropical climate and a preferably semi-shaded position, even if it bears the full sun, and soils rich of organic substance, acidic or neutral, perfectly draining, maintained constantly humid, but without stagnations. It well adapts to the cultivation in capacious pots, utilizing an organic substratum with addition of siliceous sand or perlite for a 30% to improve the drainage, for the decoration of patios and balconies or for being sheltered in the winter months in greenhouses, verandas or luminous winter gardens, out from the tropical and subtropical zones; it requires high values of ambient humidity and of day temperatures, ideal 24-26 °C, with lowest night values not under the 15 °C.
Watering must be regular and abundant in summer, avoiding stagnations, cause of easy rottenness, more spaced in winter, but without ever allowing the substratum to dry up completely, with fertilizations done preferably with slow-release balanced products with addition of microelements. It is easily subject to mites and mealy bugs attacks, to be treated, in case of serious infestation, with specific products, and is sensitive to fungal diseases in conditions of high humidity, over the 95%, and temperature, in particular to the anthracnose ( Colletotrichum gloeosporioides Penz.). The cut inflorescences, long-lasting, 10-15 days, are much required for the floral compositions.
Synonyms: Heliconia biahij Vell. (1827); Heliconia aureo-striata Bull. (1881); Bihai wagneriana (Petersen) Kuntze (1891); Heliconia elongata Griggs (1903); Bihai elongata (Griggs) Griggs (1904); Heliconia lennartiana W.J.Kress (1986).
The photographic file of Giuseppe Mazza