Philodendron spp.

Family Araceae > Subfamily Aroideae > Tribe Philodendreae.
A large genus with around 500 (450–750) species with many grown as ornamental or indoor plants.
From small to huge plants they are mainly epiphytic or climbers but can take various forms.

  • small, terrestrial herbs or tree-like plants with a thick trunk – often seen in cultivation.
  • terrestrial vines climbing by encircling upright supports then sometimes converting to epiphytes.
  • purely epiphytic with masses of long aerial roots which reach the ground.

Roots can be in the soil or aerial.
Aerial roots arise mainly from the nodes and can serve 2 functions – shorter ones attaching the plant to
    supports and long thick ones reaching the ground and absorbing water and nutrients.

Leaves are alternately arranged.
They vary a lot between species and there are different juvenile and adult leaves.
Adult leaves are needed for identification.

In seedlings the leaves are usually heart-shaped.
The change to typically large and glossy adult leaves is gradual.
The overall shape varies greatly – ovate, linear, spear shaped etc.
Adult leaves can be entire, variously lobed or deeply cut, or palmately divided with cleft lateral lobes.

Leaves are usually green but can be reddish or purplish.
The veins are sometimes white or red instead of green.
Developing leaves are protected by a modified leaf called a cataphyll.
These are usually green and leaf-like, can be persistent or turn brown and fall off leaving a scar.

Inflorescences have a central axis with tiny flowers (the spadix) surrounded by a modified bract (the spathe).
Some plants have single inflorescences, others up to a dozen on short stalks.

The lower tubular part of the spathe is often a different colour to the upper expanded blade.
Other times the inner and outer surfaces are different colours.
Colours include white, cream, green or shades of red.
The spadix is usually white.

Flowers are unisexual with the males above the females and separated by an area of sterile male flowers.
Sometimes the tip has sterile flowers.
Self pollination is prevented by the separation and by male and female flowers opening at different times.

Flowers have no perianth.
The number of carpels and locules in the ovary varies with the species.
The pollen is shed in strands.

A sticky resin is produced from most parts of the plant including the inflorescences.
(Monstera also produces resin on the spadix.)
Initially clear, yellow or red it becomes brown when exposed to air.
Some plants have extrafloral nectaries.

The fruit is a berry and is protected by an enlarging spathe until ripe when the spathe falls off.
Berries are mostly white or yellowish.

There are numerous cultivars that vary in leaf size, shape and colour.