Araceae

Aroid Family

By George Rogers

            A large, diverse, horticulturally important monocot family characterized by usually expanded (with blade and petiole) leaf blades having sheathing bases, a specialized bract around the flowering spike called the spathe, and a fleshy flowering spike called a spadix.

            Due to subtle differences, hybridization, and extensive horticultural modification producing innumerable cultivars, taxa of Araceae are particularly difficult to characterize and identify.

Aroids native to South florida include:

Arisaema triphyllum (Jack-in-the-Pulpit)

Orontium aquaticum (Golden-Clubs)

Peltandra virginica (Arrow-Arum)

Pistia stratiotes (Water Lettuce, nativity controversial)

And various duckweeds (Lemna, Spirodela)

Key to Commonly Cultivated Araceae in South Florida (includes data from BA1)

1. Leaves parallel-veined…2

1. Leaves net-veined…5

2. Plants with fragrance of anise (licorice) when crushed; petiole usually spiny…Homalomena

2. Plants not smelling of anise; petiole smooth…3

3. Plants often vines (or erect); leaves often lobed (or entire); leaf blades with a vein running along the edge of the basal notch; stamens fused…Philodendron

3. Plants erect; leaves entire; leaf blades without a vein bordering the basal notch (usually without a notch); stamens separate (in Dieffenbachia)…4

4. Side veins 3-10 pairs; stem generally inconspicuous…Aglaonema

4. Side veins 9-20 pairs; stem usually conspicuous…Dieffenbachia

5. Plants with clear sap…6

5. Plants with milky sap…9

6. Leaf blades with holes…Monstera

6. Leaf blades without holes…7

7. Stem elongate, a vine…Epipremnum

7. Stem short…8

8. Spathe flat, bright white or greenish, not waxy; leaf blades not lobed;

stigma 3-4-lobed…Spathiphyllum

8. Spathe bent back, with curled margins or otherwise not flat; variably colored, often reddish (sometimes white or greenish), waxy; leaf blades often lobed; stigma faintly 2-lobed…Anthurium

9. Leaves brightly colored usually with reddish hues (or infrequently green and white), peltate; style absent; plants usually <2’ tall…Caladium

9. Leaves green or patterned with white or cream, usually with no red, having the petiole attached near the basal notch,  or peltate; plant size variable, often > 2’ tall; style present…10

10. Leaves distinctly peltate…Colocasia

10. Leaves with the petiole attached at or near the basal notch…11

11. Leaves with the inner margins of the basal lobes concave; basal lobes with a marginal vein; ovules anatropous (bent)…Xanthosoma

11. Leaves with the inner margins of the basal lobes convex or straight, the vein separated from the margin; ovules orthotropous (straight)…Alocasia