IN THE BEGINNING, THERE WAS ARISAEMA TRIPHYLLUM
I remember being fascinated by these bizarre plants as I
roamed the woods as a child, here in piedmont North Carolina. The
native species A. triphyllum was so variable, that it made each
plant seem special. A trip one week would find the new leaves just
pushing through the leaf debris. Rushing home from school and out
into the woods a few days later would find the unfurling flowers.
Still later in the week, the purple coloration would be evident as
I picked out my favorite plant.
Having only two native species, A. triphyllum and A.
dracontium I longed to see more of what the genus offered.
Unfortunately when the continents broke apart, most of the really
wonderful species headed for Asia. Although a few seed would
occasionally make their way into this country, it wasn't until the
1990's that we really began to gain access to many of the nearly
150 species of mostly Asian arisaema.
Our native Arisaema triphyllum and A. dracontium are two of
the most hardy species, with each growing well into zone 3 and 4.
There are a number of forms/subspecies of each varying in size and
color of the flower. We'll leave the arguing over these to the
taxonomists.
In 1996, I was fortunate to spend a month in Yunnan, China
studying arisaema, followed in the fall of 1997 with a similar trip
to Korea. In the interim time, our friend Barry Yinger has helped
us set of a connection with a Japanese nursery that produces a
variety of arisaema from seed. Thanks to a "harmonic arisaema
convergence" we are now able to supply one of the finest
collections of propagated arisaema in the country.
ARISAEMA SEX:
Arisaema flowers consist of many parts, the two most prominent
are the spathe and spadix. The spathe is the hood of the pitcher,
while the spadix is the "stalk" inside the flower that holds the
sex organs. In some species the spathe develops into a long
threadlike tail, while in other species, it is the spadix that
copies this habit.
If you are the voyeuristic type, then you will love arisaemas.
Arisaema plants are one of the more unique members of the plant
kingdom. Some plants are male, some are female, some are both, and
some change back and forth (paradioecious). As a general rule,
arisaemas are male when young, then when they build up enough
energy to have babies, they switch and become female. The year
after giving birth (fruiting), they will often revert back to being
male.
There are only a few arisaema species that always have both
sexes on the same plant. They are A. flavum (always), A. tortuosum
(when mature), A. consanguineum (when mature), A. heterophyllum
(when mature), and A. dracontium (when mature but not self
fertile).
MEXICAN SPECIES:
We strongly feel that the exploration of Mexico will result in
a number of new arisaema species. While there are only 2
documented species, plant exploration by John Fairey and Carl
Shoenfeld at Yucca Do seems to have already resulted in 6 very
different collections (species?). We anxiously await these species
getting into the trade for further study.
ASIAN SPECIES:
My first encounter with an Asian arisaema was A. sikokianum.
This Japanese native was truly one of the most popular plant
imports from Japan for a reason. The stunning black purple pitcher
contrasted dramatically with the white center. I remember the $100
price tag, that left me with the feeling that I would never be able
to own one of these gems. Finally the abundance of both imports
and seed producing plants have brought the price into a more
affordable range.
The next of the Asian species to grace my garden was Arisaema
ringens...the cobra lily. This Japanese and Korean species occurs
in very low areas in densely shaded woods. I was fortunate to find
this species on my 1997 Korean expedition. The large trifoliate
leaves serves as a backdrop to the wonderful flowers. Arisaema
ringens is very early to emerge in spring, and should be protected
when a late frost is imminent. Conversely, the seed are the last
to ripen, often 2-3 months after the foliage has died away (around
Christmas).
One of the easy to grow, but spectacular species is the giant
Arisaema consanguineum. Hopelessly confused with A. erubescens,
this arisaema has one of the widest distribution ranges of any
species. Throughout our entire trip to China, we found Arisaema
consanguineum from the tropical zone 11 areas to the top of alpine
mountains at 15,000' near Tibet.
Arisaema vary as to their emergence dates in spring. For us
the first species to emerge is A. japonicum (late February),
followed soon by A. ringens, the in late March by A. sikokianum.
A. consanguineum, A. flavum, and A. candidissimum often don't
emerge until May or June in the south. You will need a great deal
of patience to grow these species. Many of these species are not
even shade plants. Arisaema candidissimum grows among dry sunny
boulders on baking hillsides. A. flavum is also a species that
prefers sun to shade.
I will admit to almost having given up after killing hundreds
of the himalayan species (i.e. A. griffithii, A. intermedium, A.
speciosum, A. costatum, A. jacquemontii, and A. nepenthoides).
According to Guy Gussman and Wilbert Hettersheid who have had
similar experiences, these tubers do not like to be dry during
their dormant season (opposite of most other species). It seems
that their roots remain growing during dormancy and must not be
allowed to dry.
PROPAGATION:
Propagation of arisaema is almost entirely from seed.
To get seed of most species, you will need both a male and female
plant (see Arisaema sex). Obviously, the more plants of a
particular species, the more chances for setting seed.
After the seed are harvested, they should be first cleaned (the
pulp contains a germination inhibitor). The easiest way to clean
arisaema seed is to put the ripe seed into a ziploc bag (the fruit
are toxic and can cause severe skin irritation and numbness) and
"squish" the pulp from the seed. After adequate squishing has been
complete, pour the mess into a cup of water. Decant the pulp
several times, and you will quickly have a cup of clean seed.
Arisaema seed can be planted in a pot of potting soil indoors
immediately after cleaning. The seed should be covered lightly with
potting soil. Arisaema seed will usually sprout within 4-6 weeks
and will proceed to grow for up to 2-4 months. At this time, they
will appear to slowly turn yellow and die. Fear not, for they are
only going dormant. When dormant, arisaemas in containers must not
be kept wet...this is certain death for most species. I keep my
plants in containers and water only when the soil gets bone
dry...about twice a month.
These arisaemas may be kept this way until winter, when after
a cold period, they will again resprout. Some of the warmer
growing species will actually resprout during the summer and put on
an extra growth cycle (especially A. consanguineum). To squeeze
out an extra season, the dormant plants can be refrigerated for 3
months during the spring/summer. This can be accomplished in the
container (if your refrigerator and spouse will allow) or by
placing the tubers in a ziploc bag of slightly moist peat(easier to
store in the refrigerator). After this time, they will resprout
and can often be forced into two seasons of growth during a
calender year.
From seed, expect it to take 2-4 years to have a flowering
size plant...depending on species. The size of the seed determines
the amount of food reserves, and consequently how large the plants
will grow during the first season. A. franchetianum, A.
candidissimum, and A. taiwanense get quite large from seed during
the first growing season.
The are other extremes, (i.e. Arisaema elephas, A. thunbergii,
and A. urashima), which only sends out a root during the first
season. Only after a dormancy period the new leaf emerges. This
could have been easily predicted due to the tiny size of the seed
in this species, as compared to the relatively large seed size of
those mentioned above.
While tissue culture has been attempted on arisaema, their
complex dormancy patterns and difficulty of sterilization, has here
to for rendered such impossible.
Some of the arisaema species actually multiply by offsets.
Arisaema candidissimum, A. amurense, A. concinnum, A. costatum, A.
exappendiculatum, A. ringens, and A. ternatipartitum are good
candidates for this mode of propagation. The small offset
bulbs/runners can be snapped off and replanted at the end of the
growing season in fall.
ARISAEMA DISEASES:
Fortunately, diseases that affect arisaema are
rare. About the only problem is from a rust fungus (Uromyces ari-
triphylli). The fungus appears usually on the underside of the
foliage, and is evident as the foliage unfurls. There is little
that can be done, except to discard the tuber to prevent spread.
Occasionally, this can be seen in the wild on A. triphyllum.
ARISAEMA HARDINESS:
Below is a compilation of arisaema hardiness
ratings that we have compiled. We include the lowest temperatures
that each species has tolerated without the benefit of snow cover.
We always welcome additional input.
Arisaema amurense (zone 4-9, Ontario) -30F
Arisaema angustatum peninsulae (zone 7-9, RI) 0F
Arisaema bockii (zone 5 Ithaca, NY) -25F
Arisaema candidissimum (zone 5a Northboro) -20F
Arisaema caudatum (zone 8b Hamilton, NZ) 15F
Arisaema ciliatum (zone 7a Dover, DE) 0F
Arisaema concinnum (zone 7-9 RI) 0F
Arisaema consanguineum (zone 5a Hubbardston,MA) -20F
Arisaema costatum (zone 7-9 RI) 0F
Arisaema dracontium (zone 4, Canada) -30F
Arisaema erubescens (zone 8b Hamilton, NZ) 15F
Arisaema exappendiculatum (zone 7) 0F
Arisaema fargesii (zone 6 Kansas City, MO) -15F
Arisaema flavum (zone 4-7, VT) -30F
Arisaema franchetianum (zone 7, RI) 0F
Arisaema fraternum (zone 7 Wrexham, ENG) 5F
Arisaema galeatum (zone 7 RI) 0F
Arisaema griffithii (zone 6-9? RI) 0F
Arisaema helleborifolium (zone 7b Wrexham, ENG) 10F
Arisaema heterophyllum (zone 5 Girard) -25F
Arisaema intermedium (zone 7-9 RI) 0F
Arisaema jacquemontii (zone 5b North Reading, MA) -20F
Arisaema japonica (syn: serratum) (zone 5 Northboro, MA) -20F
Arisaema kiushianum (zone 7 RI) -10F
Arisaema macrospathum (zone 7 RI) 0F
Arisaema nepenthoides (zone 6b-9? Dover, DE) -5F
Arisaema ochraceum (zone 7-9 RI) 0F
Arisaema peninsulae (zone 8b Hamilton, NZ) 15F
Arisaema propinquum (zone 7-9?) (zone 8b Hamilton, NZ) 15F
Arisaema ringens (zone 5 Girard) -25F
Arisaema robustum (zone 6 York, PA) -15F
Arisaema sikokianum (zone 4 Minneapolis, MN) -30F
Arisaema sikokianum x takedae (zone 6b Washington DC) -5F
Arisaema speciosum (zone 7 RI) 0F
Arisaema stewardsonii (zone 4, Canada) -30F
Arisaema takadae (zone 7a Great Falls, VA) -5F
Arisaema thunbergii (zone 5-9? Northboro, MA) -10F
Arisaema tortuosum (zone 7a Great Falls, Va) -5F
Arisaema triphyllum (zone 3 Canada) -40F
Arisaema urashima (zone 5-8, Ithaca NY) -25F
Arisaema verrucosum (zone 7-9?)
Arisaema yamatense (zone 7 RI) 0F
Arisaema yunnanense (zone 7 RI) 0F
I would like to thank everyone, especially those members of
the arisaema round robin () who
contributed information to this report.
For more information on Arisaema, we suggest reading:
Aroids by Deni Bown (Timber Press) Out of print temporarily
Himalayan Cobra Lilies by Pradhan (UK)
Be sure to visit our on-line catalog for a listing of available arisaema, with links to plant descriptions and great pictures.