BRIEF SUMMARY OF THE INVENTION
The new variety of Hosta is a tissue
culture derived sport of the species
Hosta plantaginea. I
(Clarence (C.H.) Falstad, III
) originally
discovered the plant in a cultivated
state as a sectorial chimera in some
test tubes of tissue cultured
Hosta plantaginea at a
nursery in Zeeland, Mich. The plant, with its novel
white variegation, has been produced
in a stable periclinal form. The new
variety is hereby named the 'White
Margin' variety and is sold under
the "White Shoulders" trademark.
A sexual propagation of the new
cultivar by tissue culture as well
as by rhizome division in a nursery in Zeeland, Mich., has conclusively
shown that all characteristic and
distinguishing features of the
cultivar are faithfully transmitted
or passed from one generation to the
next by such means, and that the
cultivar is stable.
BRIEF DESCRIPTION OF THE
DRAWINGS
The invention is illustrated in
the attached photographic drawings
in which:
FIG. 1 shows the plant with a
leaf having a narrow, white margin;
and
FIG. 2 shows the plant with a
leaf having a wider, white margin.
DETAILED DESCRIPTION OF
PREFERRED EMBODIMENT
The species
Hosta plantaginea is
a densely rhizomatous herbaceous
perennial with a short subterranean
stem and has petioled, tufted
leaves. The glossy surfaced leaves
are ovate to cordate-ovate and have
nine (9) to eleven (11) vein pairs.
Leaf dimensions are approximately
nine and one-half (91/2) inches to
ten (10) inches long and six and
one-half (61/2) inches to seven (7)
inches wide. Foliage height is
approximately twenty (20) inches to
twenty-four (24) inches and bears
twenty-six (26) to thirty (30) white
fragrant funnelform flowers, each
three (3) to five (5) inches long,
on a thirty (30) inch capitate
raceme or rarely panicle. The
dimensions and flower number are
dependent on environmental
conditions and cultural practices,
and therefore may be slightly
greater or smaller. In Michigan, the
plant blooms from mid-August to
mid-September.
The species
Hosta plantaginea is
quite uniform in appearance and does
not have a large number of varieties
or subspecies. The principal form of
the plant is generally known by the
species name
Hosta plantaginea. Some
variants that have been developed
have been given distinct variety
names. There appear to be two forms
of the principal specie that is
called
Hosta plantaginea. These
appear the same and are
differentiated only by the size of
the flower. One size is considered
to be the normal or average form and
the other is considered to be larger
than normal. The present invention
was derived from the normal form of
the species known as
Hosta plantaginea.
Hosta plantaginea is one of only
two species of this genus that are
native to, and only to, the mainland
of China. The other species,
Hosta ventricosa, flowers much before
Hosta plantaginea, thus preventing
any likelihood of interspecific
cross pollination. All other species
discovered to data have come from
either the islands of Japan or a few
from those of Korea. Being so
geographically isolated, an
intrabreeding species population
will tend to become more identical.
Hosta plantaginea also has many
traits consistent with a plant of a
tetraploid nature (having twice the
normal compliment of chromosomes). A
natural doubling of the chromosomes
would tend to produce a more
homozygous population resulting in
nearly identical appearing
individuals.
The new variety has the
characteristics of the original
species but is distinctive from the
original species in one main
characteristic. The plant has
basally-tufted, glossy surfaced
leaves with a lighter variegated
margin. The margin of each leaf has
an irregular lacerated pattern
frequently protruding toward the
mid-rib. In areas where the margin
tissue folds over the center green
tissue an intermediate color
results.
The colors of the plant have been
determined by referral to the R.H.S.
Colour Chart published by The Royal
Horticultural Society of London. The
intermediate color is a light
pea-green, between Royal
Horticultural Society Horticultural
color chart Number 61/2 and 61/3.
The margin emerges in the spring as
a Dresden Yellow 64/3 and gradually
lightens to white as the season
progresses. The center of the leaf
can be as light as a lettuce green
860 in nearly full sun in Michigan
or as dark as between Scheeles Green
860/1 to Spinach Green 096/01 in
deep shade and with good nutrition.
The width of the margin varies with
maturity from as narrow as
one-sixteenth (1/16) inch to as much
as three-quarters (3/4) of an inch
or more when mature. Environmental
conditions, cultural practices and
rate of growth also affect the
extent, color, and width of the
margin.
The growth of Hosta 'White
Margin' is essentially the same as
that of the parent variety of
Hosta plantaginea species. The plant grows
much better with ample water, but an
established plant can withstand some
brief periods of drought. Flowering
is more prolific with more sun, but
it produces ideal growth in Zeeland,
Mich. with a few hours of light
shade during the hottest part of the
day. The plant is resistant to most
major disease problems. The rhizomes
survive sub-zero temperatures, but
the foliage is not frost hard and
can be affected by late spring
frosts.
The variegation is a mutation of
the outer layer of the meristem.
This layer is sometimes referred to
as the L-1 layer. As this layer
forms the edge of the leaf and the
petiole is also part of the leaf, in
a monocot such as hostas the petiole
expresses the same variegation. The
color of the variegation in the
petioles of the plant usually shows
more yellowing as the petiole is in
a more shaded area and not as
lighted by the sun.