Podocarpus

Australasian Podocarps

Podocarpus is a genus of trees and shrubs, primarily restricted to the southern hemisphere. Most of the 100 or so species in the genus are dioecious (meaning that individuals produce either male or female reproductive structures – not both) and possess elongated leaves, varying from about 1/2 to 6 inches in length, with a distinct midrib.

Members of this genus are close relatives of the African genus Afrocarpus, which is also part of the family Podocarpaceae. The two to six recognized members of Afrocarpus were formerly classified in the genus Podocarpus and some texts still refer to these African species as such.

Modest Sizes

Most podocarpus grow as small trees or large shrubs, but the genus does exhibit some diversity. For example, like many species within the group, broadleaf podocarps (Podocarpus nagi) reach little more than 25 feet in height, while the tōtara (Podocarpus totara) occasionally exceeds 100 feet in height. Horticulturists have also created a number of cultivars that exhibit unusual growth forms or habits.

Fantastic Fruit

Like other conifers, podocarps are cone-producing plants. However, their cones do not resemble the familiar cones of pines, spruces and firs; instead, they are more reminiscent of the fleshy cones produced by junipers (Juniperus spp.). Most podocarp fruits consist of a dark-colored seed, with a fleshy red, orange or purple structure attached to the proximal side, called an aril.

Many bird species feed on the flamboyant fruits and spread the seeds in their droppings. While humans sometimes consume the fruit, many authorities caution against the practice, explaining that the seeds – and to a lesser extent, the arils — are toxic.

Male plants producing drooping cones, which produce and release pollen. Like other conifers, podocarps lack showy flowers, and are therefore wind-pollinated.

Commercial Uses and Applications

The interesting appearance of podocarps cause many landscapers, homeowners and gardeners to use them as ornamental trees. Some plant them as specimen or accent trees, while others plant them as hedges or screens. Most podocarps require well-drained, slightly acidic soil to thrive; alkaline soils can cause the foliage to turn yellow.

One particularly popular species is the Buddhist pine (Podocarpus macrophyllus), which usually grows as a large shrub or small tree. Native to southern Japan and China, Buddhist pines are often used by bonsai enthusiasts.

Allergens

Male podocarps produce an abundance of highly allergenic pollen; the OPALS allergy scale rates them a 10 (the highest score). By contrast, females produce no pollen of their own, and they actually absorb some of the pollen produced by males, which earns them an OPALS rating of 1 (the lowest possible score). Accordingly, those seeking to add podocarps to their landscape should opt for female plants whenever possible.

Urban Ambassadors

Many podocarps adapt well to urban environments. They are especially useful for locations with restricted soil areas, as the roots rarely cause damage to nearby sidewalks and hardscapes. Additionally, many podocarps are quite drought resistant and require little to no supplemental irrigation.

The branches of some podocarps droop toward the ground, where they may block visibility or access. However, this is readily rectified by removing the lower limbs on the trunk (a technique called crown raising).