HORT 302



ARACEAE ARUM or CALLA FAMILY INTRODUCTION: Plants in the Araceae are monocots. Most members of the arum family are tropical plants, though an obvious exception would be the Jack-in-the-Pulpit which grows extensively in the temperate zone. Vining forms often have large, fleshy aerial roots. Leaves can vary greatly in shape and many have deep lobes, slits or holes in them.

The inflorescence of this family is unusual, consisting of an expanded, leaf-like spathe and a column of tiny flowers, the spadix. The spathe is often colorful, as in many anthuriums and the closet plant. The spadix may have male and female flowers or perfect flowers or all types. They are tropical and many suffer chilling injury at temperatures below 50oF. They are among the easiest houseplants to grow and among the most popular. Some members of the family have toxic sap.

The genus Aglaonema goes by the common name aglaonema. There are several species used as house plants. They all have spear-shaped leaves and fleshy stems. Many different leaf variegations occur.

The showy anthuriums occur in several species of the genus Anthurium. They are grown for their bright, long-lasting inflorescencs and are often called flamingo flower. The inflorescence has a colorful, showy spathe and a tight column of flowers. Other anthuriums have showy leaves and are grown mainly for their attractive foliage.

Caladium humboldtii is the common caladium used both in outdoor gardens and as a houseplant. Caladiums have showy leaves with many different types and color patterns.

Several species of the genus Dieffenbachia are in cultivation. This is the dumb-cane. This plant has thick, fleshy canes with large leaves clasping to the upper portion. The plant has a poisonous sap which can paralyze the tongue and throat if ingested.

Monstera is a genus of large-leaved, vining plants. The leaves often have large slits and holes in them. Monstera deliciosa produces a large white inflorescence that results in an edible fruit. This plant is often mistakenly called the split leaf philodendron.

Philodendron is a very large genus with many excellent house plants that go by the common name philodendron. Vining and non-vining forms occur. Large and small leafed species occur and they produce many different leaf shapes. Some are green and others have bronze, yellow, black or red pigments in part or all of the leaf. Cut-leafed types often have only solid leaves unless they have a support to climb on. The leaf size and form on one type may vary from small, solid leaves to huge, split leaves depending on whether the vine is left trailing downward or given support and climbing upward.

Most pothos available in garden centers and house plant collections are in the genus Scindapsus. Pothos also goes by the common name devilís ivy. There are several species in cultivation and many cultivars. The typical golden pothos has rich green heart-shaped leaves with splashes of yellow in them. Perhaps the most common cultivar is Marble Queen which has the typical heart-shaped leaves with variegated streaks of white so that the leaves often have more white than green.

Spathiphyllum is the closet plant. It gets its common name from the fact that it can survive in very low light environments. Spathiphyllum also has the common names white flag and peace lily. Its growth habit has many dark green leaves arising from a basal stem. In good growing conditions it will produce many white inflorescences with a showy white spathe and columnar white spadix.

Syngonium podphyllum has many attractive cultivars. They are called syngonium or arrowhead plant since they produce leaves shaped like arrowheads. The leaves are produced on long stems and have many variegated color patterns and shapes. Some syngoniums are dwarf and others large, some are compact with short stems and others are vining. They are often sold as nephthytis, a genus to which they are closely related but which is rarely available.

Zantedeschia is the genus of the calla lily. Callas have showy inflorescences, the spathe being white, yellow, pink or other colors. Leaves may be solid green or spotted.

General Care of Aroids: temperature: Average house temperature to warmer than average is good for most aroids. medium: Media rich in organic matter are most commonly used. Peat is often used alone for many of these plants, but any good mix with a lot of organic matter will do. Plants in this family are easy to grow and not fussy about medium as long as it is kept moist. water: The medium should be kept moist. Most will be damaged by wet medium but some can tolerate or even thrive in a wet medium. High humidity in the air leads to more attractive foliage. light: Low to moderate light. Most will burn in bright light, but will be less colorful in low light. Moderate light is usually best since it gives good color without risk of burning. fertilization: The aroids respond to fertilizer. Large leaves are the result of ample fertilizer. A fertilizer higer in nitrogen than phosphorus and potassium is common. pests and problems: Mealy bugs, scale, mites, aphids and other pests can be problems. Diseases are uncommon, but bacterial rot can affect some if they are kept very warm and humid or are stressed by cool temperatures. grooming: Remove spent leaves and flowers. If aerial roots become a problem they should be trimmed or cut out. propagation: Members of this family are very east to propagate. Stem cuttings, leaf bud cuttings, layers and division are all used. Where several methods of propagation are possible for one plant, decide on the best method for your conditions. Several leaf bud cuttings will start out smaller but in a short time lead to a much fuller appearance than one or two stem cuttings that take the same amount of propagation material.

Some common houseplants in the Araceae are Aglaonema, Anthurium, Caladium, Dieffenbachia, Monstera, Philodendron, Scindapsis, Spathiphyllum, and Syngonium. Zantedeschia, the calla lily, is also in this family.

Araceae or Arum Family

White Rajah
Flamingo Flower
Water Arum
Swiss Cheese Plant
Cutleaf Philodendron
Burgundy Philodendron
Marble Queen Pothos
Closet Plant
Candidum Fancy-Leaved Caladium
Ace of Hearts Fancy-Leaved Caladium