Dormant seed, if it is viable, respires either gaining or
losing moisture. Passiflora seed generally does not keep well but will
be triggered into germinating by the right combination of moisture,
temperature & soil. Some seed have even more specific needs such as
smoke or being exposed to stomach acid. The germinating seed is totally
reliant on its on board stored energy until it pushes its growing tip above the soil. This
main growing tip (the apical meristem, later lateral ones are just
meristems) is responsible
for all the plant's growth above ground & similar growing tips at the
end of the roots are responsible for all growth below ground.
The stem once above ground grows up towards the light & leaves unfold
like solar panels pointing towards the sun & further growing tips split off to produce new stems.
As the stems grow upwards the plant also
down into the surrounding soil. This helps to stabilize it as well as
providing water & minerals to maintain all the parts above
ground. This is non-reproductive vegetative growth which
continues as a priority until the plant matures. This growth is fuelled
The leaves absorb light energy from the sun using carbon dioxide & water to produce sugars and other organic
night when there are low light levels sugars are broken down releasing carbon
dioxide & water to keep energy production going.
At maturity, which can be defined as having the ability to produce ripe
fruit, the flowering sequence is initiated by the master gene so that as the plant
continues to grow it also produces flower buds.
These in turn develop into
flowers, which are pollinated either by the wind, or more commonly for
Passiflora by pollinators
such as bees, moths, butterflies & other insects, bats &
Pollinated flowers then turn
into fruit as the fertilized ovary swells with the seed inside & the
flower crumples. The fruit usually drop to the ground once ripe.
Plants can take from one season to many years to go through this cycle
and there are are 3 types as below:-
A plant that lives for a season or year only....such as P. gracilis, the
Annual Passion Flower. It will grow, flower, set fruit containing seed,
and die within the year.
A plant that needs two growing seasons to complete its life cycle. It grows
foliage in the first year, rests over winter & flowers, sets fruit,
and then dies at the end of the second year. I know of no Passiflora
that follow this pattern but may be wrong.
A plant that can live for 3 or more years. It may grow, flower, and set
fruit in its first year & repeat the pattern for many years after,
but equally may take a number of years to grow to flowering size e.g. P.
membranacea. Some Passiflora die back each winter & regrow new stems
from the roots, plants that can do this are described as herbaceous e.g.
Others as they mature produce more permanent woody stems but still look
vine like, & a very few have become trees e.g. P. lindeniana.