Aroids

Vocabulary

Aroid forums and rare-plant marketplaces use a consistent shorthand. Knowing it makes vendor descriptions readable and prevents bad purchases.

Spathe & spadix

The "flower" of every aroid. The spathe is the colored modified leaf (the "petal" of a peace lily); the spadix is the spike of tiny true flowers it shelters. The whole inflorescence is what tells botanists this is the family Araceae.

Fenestration

Holes that develop in mature leaves of climbing aroids (Monstera deliciosa most famously). Theory: lets wind pass through and breaks up shadows so the plant catches more dappled light on a tree trunk.

Juvenile vs mature leaves

Many climbing aroids look completely different as juveniles vs mature plants — Monstera juveniles have tiny solid leaves and only develop fenestrations and splits when given a moss pole and bright light to climb.

Petiole

The stalk between the stem and the leaf. Petiole length, shape (D-shaped, geniculate), and color are major ID features in Anthurium and Philodendron.

Geniculum

The "knee" — a swollen joint at the top of an Anthurium petiole. Lets the leaf reorient toward light.

Aerial roots

Roots that emerge from nodes along the stem. They anchor the plant to its support and absorb water and nutrients. Don't cut them off — tuck them into the moss pole or down into the substrate.

Variegation

Cream, white, or yellow patches on leaves. "Stable" variegation reproduces in offsets; "chimeral" variegation may revert to all-green. The hobby's most expensive plants are often variegated rare aroids.

Stress / sunburn

Crispy brown patches on the leaves of an Alocasia or Philodendron mean too much direct sun. Yellowing throughout = overwatered or over-fertilized; brown crispy edges = under-watered or low humidity.

Growth habits

Aroids fall into a few well-defined categories. Knowing where a plant lives in the wild tells you what it needs at home.

Care basics

Cross-cutting rules. Most aroid losses come from violating just these five.

Light

Bright indirect — east or filtered south. Direct midday sun burns most aroids. Pothos and ZZ plant tolerate low light; Anthurium, variegated Monstera, and Alocasia need much more than people expect to keep their colors and shape.

Watering

Top inch dry, then water deeply until it drains. The most common aroid killer is sitting wet — the second is letting it dry to a crisp. A moisture meter beats finger checks for big pots.

Substrate

Chunky and airy. A typical aroid mix: 40% orchid bark, 20% perlite, 20% coco coir, 10% worm castings, 10% horticultural charcoal. Roots want oxygen as much as water — bagged "houseplant soil" suffocates them.

Humidity

50%+ for most; 70%+ for the rarer Anthurium and Philodendron with thin leaves. Tip-burn and stunted new leaves are the signs of low humidity. Group plants and run a humidifier; misting alone does very little.

Repotting

Up-pot one inch when roots circle the bottom. Aroids dislike being moved when actively pushing a leaf — wait until that leaf is open. Refresh the chunky substrate every 18–24 months.

Key genera

The genera most growers collect, with the trait that makes each one a different proposition.