Bromeliaceae Plant Family
The term ‘bromeliad’ (bro-mee-lee-add) is a simplification of the scientific name Bromeliaceae (bro-meel-ee-ay-see-eye) which covers any member of the pineapple family.
The bromeliad family contains over 3000 well described species in approximately 57 genera. As well there are thousands of hybrids, many registered as well as many unregistered.
Bromeliads are divided into groups called genera. Different genera and species require varying amounts of light, water and humidity; however, the majority of yje plants in each genus often have the same general cultural requirements. In cultivation, the most commonly found genera are Aechmea, Cryptanthus, Dyckia, Guzmania, Hechtia, Neoregelia, Nidularium, Orthophytum, Tillandsia and Vriesea.
The genus Bromelia & indeed the whole group is named after the Swedish medical doctor & botanist Olaf Bromelius (1639-1705)
History of Bromeliads
We don’t know who first used the term, but it was probably a botanist or grower who tired of the cumbersome phrase species of ‘Bromeliaceae’.
How long ago the ancestral archetype of bromeliads first evolved can’t be determined, but the oldest bromeliad-like fossil found in South American rock sediments has been dated as 30 million years old & has been named Karatophyllum bromelioides. The conclusion from this is that Bromeliaceae is a relative newcomer in the plant kingdom.
Bromeliads entered recorded history about 500 years ago when Colombus introduced the pineapple (Ananus comosus) to Spain upon returning from his 2nd voyage to the New World in 1493. He found it cultivated by the Carib Indians on the island of Guadaloupe in the West Indies.
The cultivation of pineapples in Europe began in the 1600s when heated glasshouses were used. It took time for additional bromeliads to enter cultivation. In 1753 Linnaeus listed 14 bromeliads in his Species Planetarium which were listed under Bromelia (plants with spines) & Tillandsia (spineless). Other botanists subdivided these two genera & introduced Pitcairnia & Ananus. The French botanist August Jaume de Saint Hilaire established the family Bromeliaceae in the late 1700s.
During this time & the early 1800s, there was a marked increase in interest in finding & cultivating these plants. Some of the first introduced after the pineapple were Bromelia pinguin, Guzmania lingulata (1776), Bromelia humilis, Bromelia chrysantha & Bromelia karatas.
These were followed in the early 1800s by Billbergia pyramidalis, Billbergia zebrina, Aechmea fasciata (1828), Aechmea pectinata, Cryptanthus bromelioides & Vriesea splendens (1840).
In the 1800s much of the interest was centred in France & Belgium & growers in these countries plus The Netherlands started hybridising plants for the wholesale trade.
This interest continued until the outbreak of World War 1, which put a stop to these activities. Many of the large European collections were lost during this period. There was little revival of interest between the two World Wars.
After WW11, except for Professor Raugh at the University of Heidelberg & Walter Richter in East Germany, the main interest was in the USA. However Julian Marnier-Lapostolle (1902-1976) had the largest private collection in France.
The person responsible for collecting & introducing more bromeliads than anyone else is Mulford Foster (1888-1978) of Orlando, Florida, USA. His enthusiasm & introduction of new plants was primarily responsible for the formation of The Bromeliad Society as an international organisation.
Appearance
Bromeliads are a varied group of plants, adapted to a number of climates.
All bromeliads are composed of a spiral arrangement of leaves called a ‘rosette’.
The bases of the leaves in the rosette may overlap tightly to form a ‘tank’ or water reservoir. These ‘tank bromeliads’ rely less heavily on their roots for water & nutrient absorption & are more often found as epiphytes.
The more ancient terrestrial bromeliads don’t have this water storage capacity & rely primarily on their roots for water & nutrients.
There are also the non tank epiphytes like the grey leaved Tillandsias that gather water & nutrients only from the leaf trichomes.
The foliage takes different shapes, from needle thin to broad & flat, symmetrical to irregular, spiky to soft.
The foliage is the most widely patterned & coloured of any plant in the world.
All bromeliad have trichomes (scales) which serve as a very efficient absorption system. In the desert, they help reduce water loss & shield the plants from solar radiation. These plants are so heavily covered that they appear silvery-white. On many species (especially in more humid areas), the scales are smaller & less noticeable. Sometimes they form patterns & banding on the leaves.
The inflorescence (group of flowers arranged on a stem called a scape) is also regarded as considerably more diverse than any other plant family. Some reach up 10 metres tall while others are as small as 2-3 mm. With few exceptions, they are produced from the centre of the rosette. They may be branched or simple, retaining their colour from several weeks to 12 months. The scape may be long with the flowers held away from the plant (eg Alcantareas) or it may be short with the flowers nestled in the rosette (eg Neoregelias).
Root systems vary from terrestrial species with complex root systems to epiphytic species with hard wiry roots to attach to trees & rocks.
Some bromeliads are faintly scented while others are heavily perfumed (Tillandsia cyanea resembles the smell of clove spice).
The largest bromeliad is Puya raimondii, which reaches 3-4 metres tall with a flower spike 10-12 metres tall & the smallest is probably Tillandsia usneoides.
Habitat
Bromeliads are native to the tropical & sub tropical regions of South America. They grow from Virginia in Southern USA through to Argentina. Areas with particular abundance of species include Mexico, some regions of Central America, the West Indies, eastern & southern Brazil & the Andean region from northern Chile to Colombia.
Most bromeliads grow in moist mountain forests between 1500 & 2500 metres altitude where they have cloud envelopment for several hours a day & the trichomes capture moisture. A few inhabit nearly rainless coastal deserts. Some survive frequent flooding. Others grow so close to the ocean that they are subjected to salt spray that would kill most other plants.
However, no bromeliad can tolerate prolonged subzero temperatures, although a few species have adapted to high tropical mountains where nights can be frosty eg some Tillandsia still occur at 4000 – 4300 metres in Peru. Puya raimondii grows at these altitudes in the Peruvian Andes & Puya nivalis approaches the snowline in Colombia at 4800 metres.
The species Pitcairnia feliciana is the only bromeliad that is not native to the Americas. Its discovery in Guinea in West Africa was unexpected & it is thought to have reached Africa by long distance dispersal 12 million years ago.
Cultivation & uses
Humans have been using bromeliads for thousands of years. The Incas, Aztecs, Maya & others used them for food, protection, fibre & ceremony. The pineapple is the only member used for food; however several species including Caroa (Neoglaziovia) are used as a source of fibre. Pineapple stems are a source of the enzymes bromelain & papain which are used as a meat tenderizer.
Life Cycle
With rare exceptions, bromeliads only flower once & the plant slowly dies after blooming. Plants mature & bloom over differing time periods from one to many years. A strong change in conditions may trigger premature flowering especially with neoregelias.
The plant stops producing leaves & produces its flower & it will not produce leaves again. It will however vegetatively produce one to many new “offsets” or “pups”. These plants will feed off the mother until they are large enough to set roots & survive as a separate plant. The mother may survive a generation or two before finally dying thus an attractive clump is formed. Propagation of these is seldom necessary. Other bromeliads look best as single plants & the pups should be removed & established on their own.
Pups are usually produced near the base of the plant, inside the sheath of a leaf. Sometimes they are produced on long stolons or atop the inflorescence of the mother.
Propagation
Propagation can be carried out in two ways: by vegetative offsets and by seeds.
Vegetative Propagation:
Pups should be removed when they are one third to one half the size of the parent plant (taking into consideration the width & height). This will allow the mother to produce more pups. The pup should have a firm, brown base & ‘good form’ before being removed. If it feels ‘soft’, leave it for a bit longer. The first pups produced are always the strongest.
Stoloniferous pups (growing on stems) can be removed with secateurs. For pups closely attached to the mother, use a clean saw edged knife, cutting as close as possible to the mother without damaging her soft tissue. Damage to the trunk of the parent invites bacterial or fungal attack, the same applying to the pup if cut too short. It takes months for a pup to recover from too short a cut or being removed when too little. Some dust the mother & pups with fungicide (no copper). Pups growing from the centre of the mother are more difficult to remove & take practice.
Leave the pups for 24 hours before planting. Many use peat or sand or vermiculite/perlite initially till the offset produces roots before potting on into the usual potting medium. Others plant straight into the normal potting mix & make sure the pup is not too deeply planted yet is stable.
Sometimes it’s necessary to tip the plant out of the pot so you can see what you are doing. Also carefully remove any leaves obstructing the view of the base of the pup.
Give the mother a small amount of controlled release fertiliser & she will probably produce one or two more batches of pups.
The best time to remove pups is in the warmer months – mid October through to March, though some avoid the hottest part of this period. Pups removed in the cooler months will not grow & may rot.
Some bromeliads produce small grass like pups called adventitious pups eg Alcantareas. Remove them when they are 10-15 cm tall.
Vegetative propagation does not apply to all bromeliads eg some species of Tillandsia do not pup at all, but produce lots of seeds to carry on the species.
Seed Propagation:
This is a broad topic beyond the scope of this overview. Local bromeliad societies & experienced growers are a great source of information here & I hope to include it as a Newsletter topic in the future.
Bromeliads used in Landscaping
Bromeliads add great colour & structure to any garden – provided they can be protected from frosts and are grown according to their specific requirements. It’s important to plant the different varieties in the correct position to get good form & colour. They are tropical & exotic in appearance.
The larger growing bromeliads eg Alcantareas & Aechmea Carcharodon Tiger make great specimen plants.
They can be put in the garden still in their plastic pots – dig a hole to hide the pot & cover with some mulch eg Bark Chips. This allows the plants to be moved around as necessary.
Alternatively, bromeliads can be planted in the ground into 20-30cm layer of composted pine bark to ensure good drainage.
Epiphytic varieties can be attached to trees & logs in subtropical climates.