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BEN # 158
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No. 158 February 22, 1997
aceska@freenet.victoria.bc.ca Victoria, B.C.
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Dr. A. Ceska, P.O.Box 8546, Victoria, B.C. Canada V8W 3S2
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SAPROPHYTES AND PARASITES - ODDBALLS SENSU POJAR & MACKENZIE
From: Mann, H.E. & M.V.S. Raju (1996) - Blue Jay 54(4): 192.
[abbreviated introduction to the paper cited bellow]
Parasites, in general, are organisms that live on or in other
individuals and draw their nourishment from their hosts. Most
plants, on the other hand, are autotrophic, and can manufacture
their own complex nutrients independently from simple naturally
occurring substances. But even here in the green (with
chlorophyll), self-sustaining plant kingdom, evolution has
perhaps been diverted several times to produce a small number of
saprophytes and parasites.
The saprophytes are those that survive on a wide variety of
complex organic substances without depending on other plants.
Their aerial parts are non-green (lacking chlorophyll) and the
underground roots become variously modified by showing very
irregular branching. Often these irregularly branched roots
morphologically resemble corals, and hence they are called
coralloid roots, as in some plants such as Pine Sap or Indian-
pipe (Monotropa) of the family Monotropaceae, or Coralroot
Orchid (Corallorhiza) of the family Orchidaceae. Their roots are
usually associated externally and/or internally with fungi, and
such an association is called mycorrhiza.
Unlike the saprophytes, parasites depend directly on other
plants for their growth, development and reproduction. The
parasites can be classified into two types - a) complete or
holo-parasites and b) semi- or hemi-parasites. The complete
parasites are those that depend on autotrophic plants for their
living. They are non-green and cannot photosynthesize. [Broom-
rapes (Orobanchaceae), Dodders (Cuscutaceae), and Mistletoes
(Loranthaceae) can be given as an example.]
The semiparasites do contain chlorophyll but depend on other
living plants for water and other simple nutrients. [A large
group of genera in the Scroph family (Scrophulariaceae), includ-
ing Indian Paintbrush (Castilleja), some member of the Santal-
wood family (Santalaceae) such as Bastard Toadflax (Comandra),
can be given as an example.] Some semiparasites in nature may or
may not depend on hosts for their living. The former are called
obligate semiparasites; the latter, facultative or circumstan-
tial semiparasites. In all parasites the roots, usually the
lateral roots, become modified to form haustoria (the part of
the root that penetrate the host), which facilitate the uptake
of water and other nutrients from the host plant. The faculta-
tive semiparasites, under favourable growth conditions, may not
produce haustoria. (In some instances, haustoria of the parasite
become attached to its own root, causing some destruction. This
phenomenon is called self-parasitism, which is not uncommon in
parasites, especially in semiparasites.)
Mann, H.E. & M.V.S. Raju. 1996. Some parasitic plants of Sas-
katchewan. Blue Jay 54 (No. 4 - December 1996): 192-198.
RE: CULTIVATION OF CASTILLEJA [BEN # 156]
From: Mary Barkworth <stipoid@cc.usu.edu>
My advisor - Marion Ownbey commented that he had simply planted
Poa pratensis in the plots where he was growing Castilleja. At
least, that is what I think he said - it was a long time ago ...
But the experimental garden did not have shrubs in it. Has Art
Guppy tried grass (as a host)?
COMMENTS ON ARTICLE "CASTILLEJA IN CULTIVATION" [BEN # 156]
From: Loren Russell, Corvallis, Oregon <loren@peak.org>
In my experience, Castillejas do not have restricted host
ranges, nor are the hosts necessarily woody plants. I have grown
C.levisecta on for about 6 years, from a seed population given
me by Mrs. Florence Free, of Seattle Washington. Mrs. Free had
obtained seed of this species on Whidbey Island Washington, and
had maintained it in the garden for about 20 years when she gave
me the seed. She has since had to give up her garden.
Mrs. Free had started both Castilleja levisecta and C. miniata
in her garden by rubbing seed directly into mats of the New
Zealand composite Raoulia levisecta, growing in her rock garden.
Both Castillejas had become self-seeding in this rock garden,
among a great variety of exotic and native plants.
I sow Castilleja levisecta in 4-inch pots in mid-winter, and
germination is usually complete by mid-March; seed sown outside
after the end of February will not germinate. (This and other
observations indicate that this is a D-40 germinator in Norman
Deno's terminology.) The seed of C.levisecta, and probably of
most Castillejas is very long-lived in dry storage. Some of the
original batch of seed from Mrs. Free's garden germinated last
winter, about 6 1/2 years after harvest. The seed had been
stored dry in a basement room at about 15-20 C, without desic-
cants.
Castilleja levisecta grows on very well to about the 6-leaf
stage, after which it is necessary to transfer the seedlings to
a host. Acceptable hosts have included Raoulia tenuicaulis,
Festuca ovina, Aster alpinus, Potentilla megalantha. While all
of these are exotic species, it is clear that C.levisecta can
successfully establish root connections with a great range of
host plants of diverse taxonomic groups.
PAINTBRUSH - CASTILLEJA CAN GROW WITHOUT A HOST
From: Jon Splane <jons@EFN.ORG> originally posted to
Alpine-L the Electronic Rock Garden Society
<ALPINE-L@NIC.SURFNET.NL>
I have grown and bloomed for a couple of years several clones of
what I identified as C. hispida. These were grown from seed in
pots of a soilless mix based on composted fir bark with a sub-
stantial amount of pumice added. No "host" plants were present,
although weeds frequently appeared. Weeds were removed whenever
noticed. Moss also colonized the pots and was pretty much a
permanent fixture. I doubt the Castillejas were able to use the
moss as a host.
The seedlings made very slow growth for most of their first
season, but appeared healthy. The pots were constantly moist and
fed with slow release fertilizer and an occasional shot of
soluble. They were well, but not extravagantly fertilized. The
second season they got the same culture and grew moderately well
and bloomed in mid summer.
The following spring a took some cuttings from these plants.
When the new shoots were just poking up through the ground I
removed half a dozen of these right were they were attached to
the crown. These rooted easily under cover in a mix similar to
the one growing the mature plants but with more pumice and no
fertilizer. Most grew on after being potted up and eventually
bloomed.
These Castillejas were around a couple more years and bloomed
but never looked like they were happy. They might have done
better in the ground. When I've seen this species in the wild it
has been growing in a fairly clayey loam with good drainage and
little organic material in the soil. I don't think their even-
tual demise was due to lack of a host.
[Similar observations were reported by L.R. Heckard in 1962, in
the article on "Root parasitism in Castilleja" published in the
Botanical Gazette, 124: 21-29.]
ERRATA
BEN # 154 - YUKON COLLECTING PERMITS -I made a mistake in phone
number for the collecting permits. It was given as 668-5363
it should be 667-5363. I hope you can distribute the change
with my apology. - Bruce Bennett
BEN # 156 - Apologies for the German spelling of Kamchatka. - AC
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