"tetra" means four

While scanning a list of NZ's epiphytes, vines and mistletoes to find inspiration for this week's blog, I noticed that three species - one epiphyte, one vine, and one mistletoe have similar specific epithets (the second part of their scientific name):

Passiflora tetrandra - kohia, NZ passionfruit (vine)
Peperomia tetraphylla - peperomia (epiphyte)
Peraxilla tetrapetala - pikirangi, red mistletoe (mistletoe)

"tetra" means "four" when used in the formation of compound words. The people who named these species were giving us clues by describing their features. So what does each mean?

Passiflora tetrandra = four stamens

Flowers of Passiflora tetrandra. Photo: Dr. Les King.

The yellowish-green flowers of our native passionfruit have four stamens. This species is the only tendril climber in New Zealand and is known for its small, bright orange, spherical fruit.

Peperomia tetraphylla = four-leaved

The sets of four leaves on Peperomia tetraphylla stems. Photo: C. Kirby.

The leaves of this succulent epiphyte are arranged in fours. This species has minute flowers on spikes that occur on the end of stems. It only grows in the northern North Island.

Peraxilla tetrapetala = four-winged

The four petals of Peraxilla tetrapetala. Photo: Wildlife travel.

This must refer to the four flower petals that burst apart when their fused tip is broken by a nectar-hungry bird. This species mainly grows on beech trees in the North and South Islands and is classified as "declining".

So what about the meaning of the genus names? Well according to the NZ Plant Conservation Network:

Peperomia is from the Greek peperi (pepper) and homoios (resembling), referring to its resemblance to a true pepper (to which it is closely related)

Passiflora simply means "passion flower"

But I haven't yet found information for the meaning of Peraxilla - does anyone out there have information??