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Cupheas at Strybing Arboretum
MARTIN GRANTHAM
Cuphea: from the Greek kyphos, curved, alluding to the curved
fruit capsule
Hyam and Pankhurst, Plants and Their Names
C
uphea is a genus of about 260 species in the
. loosestrife family (Lythraceae), the same
family as crape myrtle (Lagerstroemia). The distribution of this genus extends from central and
eastern North America to Brazil and Northern
Argentina. Growth forms range from upright
annuals or spreading herbaceous perennials to
woody shrubs in the range of six to ten feet.
Many are exceedingly floriferous, and perennial species may flower almost the year round
in coastal California gardens.
The flowers of Cuphea are either borne singly,
in axillary clusters, or on terminal racemes.
Each consists of a floral tube (referred to as a
calyx tube in many references) created by the
union of calyx and corolla throughout all or
part of their lengths. This structure is often
spurred below and may bear either six or two
apparent petals emerging from the floral tube
by narrow bases. Sometimes there are no visible petals. When there are six petals, two on the
top of the tube —a dorsal pair—tend to be
enlarged and showy. It is this dorsal pair that
remain in those species with only two prominent petals; these species are often referred to
as having “bat-faced” flowers. If one looks
closely, particularly with a hand lens, the full
complement of petals and sepals may sometimes be seen as tiny appendages at the tip of
26 /Pacific Horticulture
the floral tube. Flowers are visited predominantly by bees in some species, and by
hummingbirds in others. Syrphid or hover flies
have a voracious appetite for the pollen. Seeds
are produced in a capsule that splits open along
one side. Mature capsules often protrude from
floral tubes that are still showing good color.
When the capsules open, a quick look may give
the impression that these saucy little flowers
are sticking out their tongues at the gardener.
Self-sowing is common.
Mexico has been a particularly rich source
for the species in cultivation. The two most
widely known are cigar flower or firecracker
plant (Cuphea ignea) from Mexico and Jamaica
and false heather (C. hyssopifolia) from Mexico
and Guatemala. These once were about the
only species readily available in West Coast
nurseries. In the last few years, the selection
has been increased with the addition of some
reliable garden performers. Several have
entered California horticulture through the
work of botanist Dennis Breedlove, formerly
with the California Academy of Sciences in
San Francisco’s Golden Gate Park. Nearby
in the park, Strybing Arboretum and Botanical Gardens has been a repository for
Dr Breedlove’s horticultural collections since
he began his work on the flora of Chiapas,
Oct/Nov/Dec 2002
Mexico’s southern-most state.
With only a few wild cupheas in cultivation,
there are surely more good horticultural subjects in the genus awaiting introduction. As
many of us growing several species together in
the confines of our gardens have discovered,
Cuphea tends to be promiscuous; herein may lie
a source of confusion, but also exciting
potential for future garden-worthy selections.
As you will see in the following descriptions,
almost the full range of habit to be found in this
rewarding genus is represented among the
cupheas growing at Strybing Arboretum.
Horticultural characteristics shared by most
include: easy propagation and rapid development from seed or cuttings, a requirement for
regular watering, an ability to thrive in bright
shade to full sun, adaptability to a variety of
soil types, a low requirement for fertilization,
frost tenderness to varying degrees, a freely
branching habit, copious flower production
over a long period, and vulnerability to few
pests or diseases when grown outdoors. White
fly and aphid infestation can cause problems in
a greenhouse situation.
A Sampling of Cupheas
Cuphea aequipetala has been in cultivation for
some time, but plants available in California
today probably derive from Breedlove’s collections in Chiapas; it has been grown at Strybing
Arboretum since at least 1991 and at UC
Botanical Garden (UCBG) in Berkeley since
1981. The natural range for this species extends
from southern Mexico to Guatemala. The common name in Veracruz is apancholoa. In
Chiapas, plants are found at elevations of 4,000
to more than 9,000 feet in pine/oak, liquidambar, and evergreen cloud forests, as well
as on disturbed slopes and pastures. It reportedly has been used medicinally for painful urination. Young plants in cultivation grow
initially as six- to eight-inch tall, spreading
mats that can reach two feet across before much
vertical growth occurs. As flowering commences, taller shoots are produced that may
reach three feet in light shade, but are
usually two feet or less. The form in cultivation
at Strybing has lanceolate or ovate leaves from
one-quarter to one and a quarter inches in
length and one-half inch in width. The flowers,
popular with bumblebees, are borne on leafy
shoots. They are small but profuse, have short
pedicels and six petals; two are reflexed and
dark purple, four are spreading and rosy
purple. The floral tube is purple and green.
Plants were severely damaged at 16° F during
the freeze of 1990, but re-grew from mulched
crowns and from seed. This species was used
successfully at UCBG as an attractive ground
cover on a steep and unstable slope. Although
prostrate stems root sparingly, the dense
shrubby mats and seedlings aid in slope stabilization. Among seedlings at UCBG, a small
percentage are extreme dwarfs. Taller, more
upright forms with slightly larger flowers have
arisen in the Upland Mexico plantings at
Strybing; these may represent variation within
the species or, as suggested by horticulturist
Don Mahoney, hybridization with the annual
C. lanceolata cultivated in the New World Cloud
Forest plantings.
A Breedlove collection without previous
cultivation history, Cuphea subuligera has been
grown at Strybing since 1984 and at UCBG
since 1976. It is found in the states of Puebla
and Chiapas, Mexico, growing at elevations
from a little under 5,000 to almost 9,000 feet
in evergreen cloud forest and regenerating
montane rain forest. It is a dense, upright,
shrubby plant, to about three feet tall and
equally wide in cultivation, although in nature
it may reach six feet in height. The leaves are
borne on short petioles and may be from two
to three and a half inches long and one and a
half to two inches at their widest, tapering to
a sharp point. The glabrous foliage is shiny
and attractive. The flowers, popular with hummingbirds and produced almost year round,
are borne on distinct racemes with short
pedicels. Individual flowers are tubular, from
three-fourths to one and one-quarter inches
in length; the tube flares at the mouth, lacks
apparent petals, and bears glandular hairs.
Flower color in the wild varies from pink
through lavender, purple, magenta, and
orange. Two color forms were originally grown
at both Strybing and UCBG, one pale
Cupheas at Strybing Arboretum / 27
The annual Cuphea lanceolata makes a handsome edging along a path at Strybing Arboretum and Botanical Gardens.
Author’s photographs
Cuphea subuligera, orange form
Cuphea oreophila, one of the more woody, upright species
that can be used as a hedge
lavender pink, the other fiery orange red.
These have since hybridized extensively to produce many intermediate colors. The orange red
flower form was grown for many years as
C. caeciliae. Local medicinal uses attributed to
it include treatments for fever, wounds,
snakebite, and eye problems. It differs from
the pink form in holding racemes higher above
28 /Pacific Horticulture
Oct/Nov/Dec 2002
Cuphea aequipetala can make
an attractive groundcover,
here seen with Tagetes lucida
Cuphea micropetala, one of the showiest, is more cold
hardy than most species
Even a species long established in horticulture, such as
Cuphea ignea, has untapped variability waiting in the
wild, as seen in this large-leafed form collected by Don
Mahoney and grown at Strybing Arboretum and
Botanical Gardens.
the foliage and bearing larger flowers. Both
forms were severely damaged at 16° F during
the freeze of 1990 and grew back weakly
from seed and mulched crowns. In Marjory
Harris’s San Francisco garden, the orange
red form has apparently hybridized with cigar
flower (C. ignea), yielding plants vegetatively
like C. subuligera, but with flowers that bear
Cupheas at Strybing Arboretum / 29