Short Note on Passiflora lindeniana in New Zealand
Laurie Meadows

Passiflora lindeniana flowers  Passiflora lindeniana

      fruit

Passiflora lindeniana flowering outdoors in Helensville, New Zealand                                              Passiflora lindeniana fruit, about actual size

Passiflora lindeniana is a very rare tree passionflower. Vanderplank (2010) assesses it as endangered in its native habitat of the cloud forests of the Venezuelan and Colombian lower Andes.

Seed purchased about 1994 (under the rules of the day,  prior to restrictions effected in 1998) successfully germinated and yielded five plants (2 of which I donated to a specialist in exotica). Two of the Passiflora lindeniana grown outdoors flowered after about ten years.  Fruit only set and matured when flowers were hand pollinated from another tree several hundred metres away. 

These small trees are very slow growing. The tallest of the three trees is only about 3.5 meters - after 24 years of growth. Mature trees in the wild are said to grow as high as 20 meters, and reach a girth of 1.25 meters. The trees have flowered since 2005, taking ten years from planting out. A third plant finally flowered for the first time in 2014, at around 20 years old. The trees flower very heavily, but unless hand pollinated, no fruit sets. The fruit are essentially inedible, so no effort was made to set fruit until relatively recently, when I came to appreciate how rare and valuable this germplasm is.

This is the first recorded flowering and fruiting of this species outside in any country of the world outside its native range (pers. comm. John Vanderplank, november 2012). (It is likely that there are other plants of this species flowering in New Zealand, as in years past there have been several references on the internet to specimens growing here. At least one plant was used as a source of cuttings, so is likely to also be ten or eleven years old, and therefore of flowering age).

All three trees growing outside are in moderate shade, one being planted under an alder shelterbelt, the other being planted at the back of a disused shadehouse, and overshadowed by an evergreen magnolia. The former plant is in a moderately well drained silty sand-clay loam, the latter is in a well drained leached sandy loam. Air temperatures here do not fall much below about 5oC, and daytime air temperatures rarely exceed 27oC in summer. This temperature range is probably similar to the high elevation limits of its natural range (2,700 meters).

None of the plants have been significantly affected by pests.

The plants normally completely defoliate over summer (appearing to be totally dead), and do not re-sprout until the rains of early autumn. Flowering occurs abruptly and en masse when the canopy has re-grown leaves.

The leaves are dark green, large and showy, slightly leathery, and robust. They gradually turn yellow over summer, and then fall.

These plants have been place in partial light shade on the assumption they are a forest margin plant. They may well grow in full sun, but I haven't tested them. They seem remarkably drought tolerant, with defoliation perhaps being an adaptation to seasonal drys.

They grow easily from seed, doing well when potted into a standard garden centre bark-based potting mix for shrubs and trees. They seem to require feeding well when young, and young plants don't normally have a summer defoliation. They are very slow growing.

I have made several successful grafts on the mature plants in place (to end the need to hand transfer pollen between distant plants), but my success rate was only around 33%. A competent grafter would likely have much greater success. In 2018 I suceeded in marcotting (air-layering) a single plant from 2 marcot attempts. The marcot was placed in March and harvested in August. Coconut coir was used as the rooting medium.