Ibicella lutea: Yet Another Note on the Carnivore from the Martyniaceae
(Bulletin of the A.C.P.S., 1994, 13:1, 6.)
I have enjoyed the recent flurry of articles regarding
Ibicella lutea (for example, Bertozzi 1993; Cekic 1993; Kane 1993).
But there is a small amount of misinformation in these otherwise fine articles.
It is clear the plant Kane (1993) described is not Ibicella lutea
(because of flower colour) but is probably Proboscidea louisianica.
Seed obtained from the same source as Kane (labelled "I. lutea")
germinated and subsequently flowered--revealing itself to
be P. louisianica. Observations of these specimens corroborated
Kane's comments on the plant's ability to capture small insects. But it will
take careful work like that of Mameli (1916) to prove or disprove the
possibility of a carnivorous nature for Proboscidea louisianica.
Because of the continued confusion about these plants, I thought I should
write a few words of clarification.
The botanical family that contains I. lutea is Martyniaceae.
Various authors--as far back as Van Eseltine in 1929 and continuing
to this day--have disagreed upon the structure of this family. They
have shifted species from one genus to the next, and occasionally
destroyed old genera or created new ones. Through the years, the carnivorous
plant known today as I. lutea has been placed
in three of these mutable genera--Ibicella, Martynia and
Proboscidea.
Fortunately there is only one plant in the Martyniaceae with the specific
epithet "lutea". So if you are reading about species in this
family and encounter I. lutea, M. lutea, or P. lutea,
it is the plant that interests the carnivorous plant enthusiast.
There are a few other genera in this family (which are not recognized
by all authors), but they are unlikely to be encountered.
These genera are mostly dryland plants--several species are native to the
desert I live in, and one (P. parviflora var. hohokamiana) was partially
domesticated by the indigenous
tribes of Arizona, USA, as a foodcrop that also had textile uses. The
possibly-carnivorous plant, I. lutea, is a naturalized weed in southern
California with origins in South America.
Suppose you are growing a plant from this family---how do you know if it
it I. lutea, and not some noncarnivorous imposter?
It is simple matter, as long as the plant is in flower.
Look at the calyx ("calyx" means all the sepals). In
Proboscidea the calyx consists of five sepals which are fused together
for about half their lengths, forming a loose sack which encloses the
corolla tube. Underneath the flower the calyx is usually slit to the base.
If you removed the calyx and flattened it, you would have a palmately-lobed
single structure, like the maple leaf on the Canadian national flag.
In contrast, the calyx lobes of Martynia
and Ibicella are completely free from each other--in these two genera,
the calyx consists of five distinct sepals.
At the base of the calyx you will see one or two leafy bracts. Do not
mistake these for calyx lobes.
If your plant has passed the first test, so you are certain it is not
Proboscidea, the next step is to determine if it is
Martynia or Ibicella. This is decided by the number
of fertile stamens in each flower. Ibicella has four functional stamens,
but in Martynia two are not fully developed and are sterile. These
sterile stamens do not support pollen-bearing anthers. Of course,
the happy CPer is one who discovers he or she has Ibicella and not
Martynia. As a final check look at the flower colour.
As Van Eseltine (1929) wrote and Cekic (1993) maintained, the corolla tube
is greenish-yellow on the outer surface, and yellow to orange-yellow
on the inner surface. (This is, of course, what the name I. lutea
is telling us.) The palate region of the corolla may be dotted with orange
or red spots, but this is not to say the flower is reddish. The flowers
are very weakly scented, while the flowers of P. louisianica
(for example) are strongly musky-sour. Another species of Ibicella
is I. nelsoniana (which is sometimes called Hologregmia
nelsoniana). This plant is distinguished by its small and
narrow floral bracts, while the bracts of I. lutea are very
similar to the sepals.
A few years ago I was finally able to find a botanical garden where this plant
is grown. A well-placed associate was able to obtain seed from this location
but despite a year's effort, neither of us have yet been able to induce
germination.
A final comment--I. lutea is reported to be more or less
sparsely covered with spines, although specimens I have examined (University
of California at Davis Herbarium) do not bear them. But if I. lutea
is often spiny, it is the only carnivorous plant to be so.
References:
Bertozzi, T. 1993. A.C.P.S. Bulletin 12:2, p. 9.
Cekic, C. 1993. A.C.P.S. Bulletin 12:2, p. 7.
Kane, P.M. 1993. A.C.P.S. Bulletin 12:1, p. 12.
Mameli, E. 1916. Ricerche anatomiche, fisiologiche e biologiche
sulla Martynia lutea Lindl. Atti dell'Universita di Pavia, Serie 2,
16, p. 137-188.
Van Eseltine, G.P. 1929. A preliminary study of the unicorn plants
(Martyniaceae): Technical Bulletin 149,
(Geneva: New York State Agricultural Experiment Station), p. 1-41.
Heckard, L.R. 1993. In The Jepson Manual: Higher Plants of California,
ed. Hickman, J.C., (Berkeley and Los Angeles: University of California Press),
p. 762.
Morley, B.D., and Toelken, H.R., 1983. In Flowering plants in Australia,
(Adelaide: Rigby), p. 275.
Postscript: In the time I wrote this, I have induced germination of Ibicella lutea, and obtained seed. Also, I learned that the spines are strictly
located on the woody fruit.