The Araceae Family – More popular than they know

By Donna Porter

If there were ever a world-wide popularity contest of families in the plant world, without a doubt, the Araceae family and its members would win – hands down.  This family’s realm of existence extends from the most frigid of northern climates to the sweltering tropical rainforest of the southern hemisphere.  Its fame is not due to characteristics such as possessing exquisitely-beautiful or scented flowers (as the orchid), or deliciously- sweet fruit (as the mango), or intricate and outrageously- colorful foliage (as the croton).  The truth is that this family’s expansive recognition is mainly due to the fact that it can tolerate low-light conditions, adapt to low-humidity environments, scoff at neglect and travel well.  And, yes, their handsomely-bold and striking foliage has also greatly helped. This renowned family of plants includes an astonishing 108 genera and nearly 3,700 species.  With the assistance of man, its celebrity members have traversed the globe from their native tropical habitats into shopping malls, offices, hotel lobbies and homes of every climate imaginable.

The Araceae family (aka the Arum family because of their typical arrow-shaped leaves) is also commonly called “Aroids” in the trade.  The most distinct and easily-recognizable characteristic of Aroids is their “flower” (or inflorescence) which is comprised of a spathe and a spadix. (The only other family possessing this flowering characteristic is Arecaceae – The Palm family). The spathe is the outer bract, which typically appears like a cupped leaf enfolding the phallic-like spadix. The coloration of the singular spathe can range anywhere from pure white (like Spathiphyllum floribundum/ Peace-Lily/Espatifilo), to greenish-white or light green, to off-white, beige, maroon, purple, red or pink.  The shape of the spathe can vary as well, from an open spoon-shaped; to spear-shaped, cupped and almost entirely enclosing the spadix; to Elizabethan-type collar – shaped; to flat, reflexed and perfectly-hearted shaped – like many of the florist cultivars and hybrids of Anthurium spp.

When it comes to size of an Aroid’s “flower”, well this family has won in both categories of extremes from the largest to the tiniest.  Amorphophallus titanium/Titan-Arum is by far the champion for its grandiose flower, and is by far one of the greatest curiosities in the plant world.   Fairchild Tropical Gardens in Miami made the news in May of 2001 when their Titan-Arum, lovingly dubbed “Mr. Stinky”, gave birth to its second bloom, ever, which measured 6.5 feet tall.  The name comes as no surprise, since the flower of this species emits a pungent, putrid aroma, much like rotting meat, that attract the carrion beetle which aids in pollination.  The honors of the tiniest known flower go to another member of the Arum Family, Wolffia arrhiza/Duckweed.

The popularity and visibility of many members of the Arum family is mainly due to their usage in interior landscapes and their huge success in the foliage plant industry.  Undoubtedly, at some time in your life, you have crossed-paths with them at shopping malls, building lobbies or had one adorning your home or office.  Some of the most popular of these durable Aroid beauties is   Dieffenbachia spp./Dumbcane/Loteria (in Spanish); Aglaonema spp./Chinese Evergreen; Spathiphyllum floribundum / Peace Lily/Espatifilo; Philodrendron spp. (numerous species), Monstera deliciosa/Swiss Cheese Plant/ Mano de Tigre; Syngonium podyphyllum/Arrowhead Vine; and Epipremnum aureum/Pothos – a vining plant with heart-shaped, green and yellow variegated leaves that can tolerate extreme cases of plant  neglect.  Caladium x hortulanum is another Aroid member that is frequently used to add splashes of color in outdoor shade gardens in the U.S., but will not survive severe winters.

Here, in Costa Rica, the land of warmth and humidity, all of these Aroids thrive with minimum care in our outdoor gardens or as potted plants.  They perform best planted in part- shade to full-shade in well-drained, humus–rich soil.  Scorching, yellowing or blanching of the leaf will occur in full-sun.     Our tropical landscapes – and forests – are teeming with Aroids.  Under tropical conditions, the leaves of Philodendron spp. or Epipremnum aureum/Pothos can grow 1-2 feet or more and climb trees to heights of  10- 30 feet.  It’s a Horticulturist’s Heaven! But, beware.  There are always the over-achievers like Syngonium podophyllum.  With its rapid and profuse vining habit it is close to being considered an invasive plant, as it already is considered in Florida.

There are numerous species in the Arum Family that are native to Costa Rica.  Probably the most popular is Anthurium cubenses/Tabacon (in Spanish translates to tobacco leaf), which is a common epiphyte in the rainforest, but can also be terrestrial. There are nearly 80 native species of Anthurium/Anturio (in Spanish); 12 native species of Dieffenbachia; 22 native species of Monstera; and 59 native species of Philodendron…. plus more.

Other noteworthy Aroids are in the genera Alocasia, Colocasia and Xanthosoma.  The genus Alocasia includes beauties like Alocasia x amazonica and Alocasia macrorrhizos ‘Variegata’ that exhibit some of the most awe-striking, arrow-leafed foliage imaginable. Taro, Colocasia esculenta, is grown for its starchy, edible corm and vitamin-rich leaf and has an amazing range of culinary usage around the globe.   (Leaves of the Taro and other Aroids contain calcium oxalate crystals, which can cause irritation of the mouth, throat and skin.  Leaves must be cooked to minimize the chemical before consumption). C. esculenta ‘Black Knight’, a cultivar of Taro, makes a stunningly- bold and contrasting addition to your garden. Xanthosoma sagittifolium/Tiquisque (in Spanish) is another edible Aroid. The plant’s tubers are high in starch and used mainly to thicken soups.  X. maffafa is the famed Elephant Ear/ Malanga which has been naturalized throughout parts of Costa Rica.  Its bold and upright presence In a tropical garden is unparalleled.

A glorious exhibit of Aroids will be found climbing trees and amongst the many display gardens and collections contributing their precious richness of green, their uniqueness of flower and their distinctiveness of  form  at the future botanical garden.

Donna is a Horticulturist and has been living and working in Manuel Antonio for 7 years.  She consults, designs, installs and maintains gardens for private homes and hotels and also develops botanical trails. Donna is the founder and first Director of the Botanical Garden of the Ozarks and is pursuing the development of a botanical garden in, and for, the Quepos area.   [email protected],  2777-5149