Amorphophallus is a genus of around 200 tropical and subtropical tuberous plant species native to Africa and Asia. They grow from underground tubers and produce a large petiole resembling a leaf stalk topped with a spathe and spadix, which is the inflorescence containing unisexual flowers. A few species have edible tubers that must be prepared carefully. The plants prefer disturbed ground and grow in tropical and subtropical zones from West Africa to the Pacific Islands.

1. Amorphophallus (from Ancient Greek amorphos, "without form, misshapen" +
phallos, "penis," referring to the shape of the prominent spadix) is a large genus of
some 200 tropical/subtropical tuberous herbaceous plants from the Arum family
(Araceae). A few species are edible as "famine foods" after careful preparation to
remove irritating chemicals.
These typical lowland plants grow in tropical/subtropical zones of the paleotropics,
from West Africa to Pacific islands. Most species are endemic, and prefer disturbed
grounds, such as secondary forests. These small to massive plants grow from a sub-
terranean tuber that varies between species, from the quite uniformally globose
tuber of A. konjac, to the elongated tubers of A. longituberosus and A. macrorhizus,
to the clustered rootstock of A. coaetaneus.
From the tuber grows a trunk-like petiole (a single leaf)—which can be several
meter across in larger species—a vertical stalk with a horizontal blade and a number
of small leaflets, which lasts one growing season. The tuber also shoots out a single
inflorescence, with a peduncle (primary flower stalk) that can be long or short.
Typical of the Arum family, the inflorescence has an elongate or ovate spathe (a
sheathing bract) which usually envelops the spadix (a flower spike with a fleshy
axis). The spathe can have different colors, but mostly brownish-purple or whitish-
green. Inside, they contain ridges or warts, functioning as insect traps.
Source: http://en.wikipedia.org/wiki/Amorphophallus

2. Amorphophallus paeoniifolius (Formlös fallos,
(English: Malformed Male Member…))
~ 50 cm (20”)
~ 50 cm (20”)

3. 10 cm
Inflorescence buds
Petiole (leaf) buds 30 cm

4. One tuber (underground yam (potato))
produces one “petiole” like this, and
one “flower” (bud shown right)
~ 15 cm
~ 25 c
m

5. The petiole (a single leaf) is fully formed inside its bud sheath, unfolding
in a few days time (picture to the right shows three development
stages)

6. ~ 50 cm (20”)
The “hat” has an uncanny likeness
to the false morel mushroom:
Also known as Pongapong, Big Stinky, Elephant foot
yam, Whitespot giant arum, Stink lily, Jimmikand,
Corpse flower, Voodoo lily, and many more… False Morel (Gyromitra esculenta) (Im

7. The petiole shows a beautiful symmetry in how the rachi and its
leaflets unfold (Right: after ~ two days; Left: after ~ five days)

8. “Spadix”
Frühlorchel (Gyromitra esculenta) (Image courtesy Wikipedia DE)
Actual
flowers
“Spathe
”

9. The Petiole: Not a stem with leaves!
“Leaflet”
“Leaflet”
“Rachi”
The large Amorphophallus tuber , grown for
food, may weigh anywhere from 3 to 25 kg
“Petiole”
The petiole is actually a single divided leaf, the “stem
proper” is the underground tuber (yam). When flowering,
the flower bud and petiole shoots up simultaneously, in only
a few days. Here in Tagaytay, the petiole (now containing
most of the carbohydrates previously stored in the tuber) is
harvested and cooked as a vegetable. Elephant Yam tuber (konnyaka potato ) (Imag

10. Stenmurkla (Gyromitra esculenta) (Image courtesy Sofia Bryntse)

11. The inflorescence is a cluster of flowers arising from the
main stem (peduncle). Amorphophallus paeoniifolius Typical Arum Family Spadix
has an enlarged, inflated, flower-bearing spadix protrud-
ing from a spathe.
The spadix grows out of a vase-shaped or funnel-like
spathe (a modified leaf), often brightly colored. In some
arums the spadix emits a putrid odor that attracts flies Spadix
for pollination.
The arum family (Araceae) spadix has a characteristic in-
florescence—a thickened, fleshy axis (spike) bearing clus-
ters of sessile, apetalous, unisexual flowers. The small Flower
unisexual flowers are packed together along the lower Cluster
region of an erect central spike, with the yellow male
flowers (stamens) above the whitish-red female stigmas
(pistils). Spathe
The upper region of the spadix usually has no flowers.
Male (staminate) flowers are numerous closely packed
stamens, and the female (pistillate) are numerous indi-
vidual pistils. Individual flowers are reduced to a single Peduncle
stamen or pistil (gynoecium).
Source: http://waynesword.palomar.edu/terminf1.htm (spadix picture copyright © 2002 E. M. Armstrong)

12. Male flowers: many, small
Pungent pheromones (smells like putrefying
meat) attract pollinators (flies, beetles) Female flowers: fewer, bigger

13. The fruits of its
labors… Ready for
distribution! The
seed bounty may
Warning: When fully ripe, the fruits are a bright yellow,
and looks delicious (much like a huge ear of corn). Do have a height of
not let this fool you (or your children) to have a taste! If
chewed, the “berries” cause an intense tongue burn
~50 cm, and a dia-
that lasts for several days! meter of ~ 8 cm.

14. Easy to see what earned it the name “Malformed Male Member”…
Amorphophallus paeoniifolius www image samples
(images hyperlinked to source web site)

15. Henry Norman
MicroTech Consulting
Tagaytay City
Philippine Islands
Googleplus/Henry.KO.Norman
Copyright © 2012 Henry Norman