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 December
2001
 Iris
unguicularis
 November
2001
Hymenoxis
herbacea
October
2001
Pellaea
atropurpurea
September
2001
Zauschneria
garrettii
August
2001
Platycodon
grandiflorum
'Sentimental
Blue'
July
2001
Callirhoe
involucrata
June
2001
Helianthemum
nummularium
hybrids
May
2001
Viola
pedata 'Bicolor'
April
2001
Anemonella
thalictroides
March
2001
Fritillaria
pudica
February
2001
Castilleja
rupicola
January
2001
Lupinus
lepidus var. lobbii
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2003
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2002
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2000
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1999
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1998
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1997
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Plant
of the Month
November
2001
Hymenoxis
herbacea
by Iza Goroff
Hymenoxis
herbacea is a member of the Asteraceae, the daisy
family. It has had a variety of botanical names applied to
it, including Actinea herbacea,
Tetraneuris herbacea, and
Hymenoxis acaulis var. glabra
(even though it is not glabrous). Its distribution is very
widely scattered with relic populations in far northern
Michigan, the Bruce Peninsula in Ontario, the Marblehead
Peninsula in Ohio, and a single population in Illinois in a
canyon near Lemont, destroyed when the local electric
utility inadvertently buried the remaining population under
a load of slag. Fortunately plants had been taken from
there, propagated, and introduced to Illinois
horticulturists (by the late Rose Vasumpaar), where it
persists in many gardens and from which a Minnesota nursery
propagates it.
Different
populations vary in the size of the individual plant. The
linear leaves can vary from 2" (5 cm) to 4" long and 1/3" (1
cm) to 1/2" (1.5 cm) wide. Flower heads are about 1.5" to 3"
wide on stems which start very short, an inch or two, and
grow to as much as 10" (25 cm) at the end of flowering. Each
flower head lasts over 3 weeks in bloom. The season in
Wisconsin can begin as early as late April and extend into
June.
All of the
populations of Hymenoxis
herbacea grow on natural limestone pavements in full
sun. However, it can grow in part sun without limestone as
long as the site is well drained and not too wet.
Plants from
a single population do not produce much viable seed,
although I have found rare self sown seedlings amoung
limestone stairs in a previous garden. If one is fortunate
to acquire plants from several of the relic populations,
fertility improves immensely. An individual plant will
produce several prostrate short stems radially from its
crown. These may have a few roots on them, but even if they
do not, they can be rooted to provide new plants.
Hymenoxis
herbacea is my favorite yellow daisy, a miniature
perennial sunflower for the rock garden.
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