allium - seeds & propagula |
Most alliums produce prodigious quantities of seed,
providing an easy and viable method of increase. In
some species, the self-seeding tendencies can be
a problem if an over abundance of seedlings are
not wanted. Allium seed tends to come in two
different basic shapes; those with flat or angular
seed (as shown above) tend to germinate freely,
whereas those with round, pellet-like seed (such
as most American species) tend to be more
difficult to germinate thus less of a problem.
Follow this link to see photos of the lovely
Allium zebdanense, a supposedly invasive
species.
|
Allium canadense - red bulbil form
No, this isn't Physoplexus comosa, it's a weedy
bulbilliferous allium found throughout the eastern
half of the United States and into Canada;
Allium canadense. In this species, the flowers are
replaced by clusters of ready-to-sprout bulbils,
which occasionally sputter forth a white flower.
This particular form from Texas is kept in my
collection because of the novel white and red
coloration of the bulbils. I carefully cut and
discard the heads to avoid unwanted spreading.
Click here to view a rare, totally floriferous
collection of Allium canadense forma
florosum.
It's a good rule of thumb to avoid alliums that
produce lots of bulbils in the inflorescence, not
only because they tend to be ugly, but the
propagules are too willing to drop off and start
new plants.
|
Allium hollandicum (aflatunense of
Hort.)
Almost all allium species occasionally demonstrate
aberrant behavior, with normal floriferous species
producing curious bulbilliferous flower heads. I'm
quite convinced that all allium species share this
genetic propensity, and I've seen bulbil propagules
on such unlikely species as A. hollandicum (shown
above), A. senescens, A. flavum, A. cernuum,
A. nutans, and others. These curious bulbil
manifestations should be of no concern, unlike
the truely bulbilliferous species, because they
are rare occurrences. |
Allium rotundum - bulbs and bulblets
Some species have a propensity to propagate
and spread via bulblets produced around the
parent bulb. Sometimes the bulblets are attached
to a slender stalk (stipitate), or they generate
close to the parent bulb as in A. rotundum shown
above. Notice how the fibrous bulb coats
swell with little clusters of tiny bulblets, eventually
breaking open to release the payload. In this
species, the bulbs grow close to the surface, and
bulblets can be found near the soil surface
and rolling about to take root close by. Even
though A. rotundum makes lots of little bulblets,
it's spread is never threatening nor overly
aggressive, and the plants grow so shallow
that they're easily removed if not wanted.
|
Photos by Mark McDonough |
