Philodendron

Philodendrons are many kinds of green plants.

Some grow high up in trees. They use roots to climb up. Other kinds start on the ground. They grow toward dark shadows to find a tree. These plants can change their leaf shapes. Small leaves grow when the plant is young. Big leaves grow when the plant is older. Some plants even make sweet juice. This juice brings ants to the plant. The ants help keep the plant safe. It is a busy world for these plants.

Philodendrons are a large group of flowering plants. Their name comes from Greek words that mean "love for trees."

Many people grow them as indoor plants.

These plants have many ways to grow. Some start high in the trees. They grow roots down to the soil to find food. Other kinds start on the ground. They grow toward dark shadows to find a tree. This way of growing toward dark spots is called scototropism.

Philodendrons can change their leaves as they age. This change is called metamorphosis. Young plants often have small, heart-shaped leaves. As they grow, they make much bigger adult leaves. Sometimes the shapes look very different!

When it is time to make seeds, they grow a special flower. It has a leaf-like hood called a spathe. Inside is a tube called a spadix. Some plants make heat in the spadix. This heat helps attract beetles. The plants also make a sticky resin. This resin helps keep pollen on the beetles.

Philodendrons are a huge group of flowering plants. They belong to a family called Araceae. Scientists have found 625 different species in this group. Many people love to grow them as indoor plants. The name comes from Greek words. One word means "love" and the other means "tree."

These plants have many ways to grow. Some are called hemiepiphytes. This means they can live in different ways. Primary hemiepiphytes start high up in the tree canopy. They grow roots down to the forest floor to find nutrients. Secondary hemiepiphytes start on the ground. They use scototropism to grow toward dark shadows. This helps them find a tree to climb.

Some plants have a special friendship with ants. The plant has glands called extrafloral nectaries. These glands make sweet nectar for the ants. The ants build nests in the plant's roots. The ants protect the plant from hungry insects. In return, the plant gets nutrients from the ant nest. This is a helpful way for both to live.

Philodendrons can change their leaves as they get older. This change is called metamorphosis. Young plants often have small, heart-shaped leaves. As the plant grows, it makes adult leaves. These adult leaves are often much bigger. They can also have very different shapes. This change happens when the plant gets more light or nutrients.

When it is time to make seeds, they grow a special flower. This flower has a leaf-like hood called a spathe. Inside the hood is a tube called a spadix. Some species can make heat in the spadix. They use stored energy like carbohydrates and lipids to do this. This heat attracts beetles to the plant. The plant also makes a sticky resin to hold pollen.

Philodendron is a large genus of flowering plants within the Araceae family. The Plants of the World Online recognizes 625 species, though other sources may list different numbers. It is the second-largest genus in the Araceae family, trailing only Anthurium. The name comes from the Greek words "philo," meaning love or affection, and "dendron," meaning tree. Many species are popular as ornamental indoor plants. Because many species remain undescribed, the genus is still considered poorly known by taxonomists.

These plants show an extremely diverse array of growth habits. They can be epiphytic, meaning they grow on other plants, or terrestrial, meaning they grow in the ground. Many are hemiepiphytic, which involves a combination of these methods. Primary hemiepiphytes begin their lives high in the forest canopy as epiphytes. Once they reach a certain size, they send aerial roots down toward the forest floor. When these roots hit the soil, the plant can finally access nutrients. This strategy prioritizes obtaining light early in life over immediate nutrient access.

Secondary hemiepiphytes follow a different path. They typically sprout from seeds on the ground or near a tree trunk. These plants use a behavior called scototropism to find a host. They grow long internodes, which are the spaces between leaves, toward dark areas like tree shadows. Once a tree is found, the plant switches to phototropic growth, meaning it grows toward light. At this stage, the internodes shorten and thicken as the plant climbs upward.

Some species have developed a symbiotic relationship with ants. Philodendrons possess extrafloral nectaries, which are glands that secrete nectar outside of the flowers. This nectar attracts ants, which often build nests among the plant's roots. The plant receives nutrients from the ant nest and protection from aggressive ants that defend against eating insects. In return, the plant provides food and a place for the nest. This relationship helps the plant survive in competitive environments.

Philodendrons undergo a process called metamorphosis regarding their leaves. Seedlings usually have small, heart-shaped leaves. As the plant matures, it begins producing adult leaves that can be drastically different in shape and size. Adult leaves might be lobed, spear-shaped, or divided. This change can be triggered by reaching a certain height or gaining access to soil nutrients. In the past, this caused taxonomic confusion, as scientists sometimes mistook juvenile and adult plants for different species.

Reproduction in philodendrons involves a unique structure called an inflorescence. This consists of a leaf-like hood called a spathe and a central tube called a spadix. The spathe often uses the pigment pelargonidin to create red or crimson colors. Inside the spadix, there are fertile female flowers, fertile male flowers, and a sterile zone. This sterile zone acts as a barrier to prevent fertile male flowers from fertilizing the female flowers. Some species even produce a sticky resin on the spadix to help keep pollen attached to visiting beetles.

One of the most amazing features is thermogenesis, or the ability to produce heat. In the sterile zone of the spadix, the plant oxidizes stored carbohydrates and lipids to generate warmth. This process is triggered by the formation of acetosalicytic acid, which causes mitochondria to use a cyanide-resistant pathway. This heat attracts beetles and helps distribute pheromones into the air. The rate of oxygen consumption during this process is remarkably high, similar to the metabolic rates of hummingbirds. This heat and the resulting infrared radiation help ensure successful pollination.