Daylilies
Daylilies have been known and grown for thousands
of years. Natives of Asia, they are featured in paintings and folk legends dating back to Confucius
(551-479BC). They were originally grown as food or medicinal plants. The Chinese name for H. fulva is
"hsuansao" meaning the forgetting bush, alluding to its tranquillizing and hallucinatory properties: the young, boiled
shoots were often given to those who were in mourning.
Daylilies first reached Europe via the trade routes: H. Iilioasphodelus (syn. H.
flava) probably arriving in Hungary,
and H. fulva in the sea ports of Lisbon or Venice. References to both first appeared in the works of the European
herbalists Clusius (1525-1609) and Lobel (1538-1616) in
the sixteenth century and in Gerard's (1545-1612)
Herball or Historie of Plantes (1597). Daylilies, along with
peonies and lilacs, were among the very few ornamental
plants taken to America by the early settlers and used in their homestead gardens.
During the last two hundred years other species have
reached Europe from Asia, including H. minor, which was
described by Philip Miller, Curator of the Chelsea Physic
Garden (1722-71), although his description is rather
vague. In the nineteenth century, plant hunters such as
Wilson, Forrest and Kingdon-Ward, found important
species, mainly in the Yangtze River Gorge country in
western China. Living plants of H. dumortieri were shipped
by Phillip von Siebold to the botanic garden in Ghent.
H. middendorffii was first collected by Alexander von
Middendorf and described by him after it had flowered in
the botanic garden in St. Petersburg. H. fulva 'Flore Pleno'
arrived in Europe in 1869, and later H. citrina and H. fulva
'Maculata' were received by Charles Sprenger and Willy
Muller (in Italy), who disseminated them, and other species, around Europe.
The first recorded daylily hybrid' Apricot' was introduced in 1893 and given the Award of Merit from the
Royal Horticultural Society in the same year. A cross
between H. lilioasphodelus x H. middendorffii, it was one of
many crosses introduced by the pioneer hybridizer, George
Yeld (1845-1953). He and Amos Perry (1871-1953) were
the only British breeders of daylilies in the early part of the
twentieth century. Perry's output was prodigious although
a large proportion of his introductions are now lost. Of
those remaining, 'Thelma Perry', a strongly scented
yellow, and 'Lady Fermoy Hesketh' are treasured by those
gardeners whose preference is for the older sorts.
In the mid-1950s two iris growers started their own
daylily hybridizing programmes. Harry Randall's' Amersham' and 'Missenden', both early red tetraploids, were
awarded First Class Certificates by the Royal Horticultural
Society. Leonard Brummitt's introductions in the 1960s
and 1970s, bearing the 'Banbury' prefix, were highly
regarded in their time but were soon superseded by the
work of Robert Coe.
Classification
The genus Hemerocallis (from the Greek hemera a day and
kallos beauty) was so named by Linnaeus in the eighteenth
century and placed by him in the Liliaceae (lily family),
along with hostas, kniphofias,
aloes and the true
lilies. It
has long been recognized that Linnaeus' lily family was
far too large to be meaningful. Under the modern
classification of the monocotyledons proposed by
Dahlgren, Clifford and Yeo (1985) and now widely used,
daylilies are placed in their own family, the Hemerocallidaceae. However, more recent molecular DNA studies
show that daylilies are most closely related to phormium,
which would place them in the family Phormiaceae, in the order Asparagles.
Habitat
The genus Hemerocallis contains (at most recent estimates) approximately 30 species of evergreen,
semi-evergreen or herbaceous (winter dormant or dormant)
perennials, natives of meadowlands, marshy river valleys
and deep, rich soils at forest margins. It is endemic in eastern Asia, according
to Chung and Kang (1994) and is found in China (north of the Yangtze river),
Mongolia, north-eastern Siberia, North Korea, South Korea (except for its
southern tip), and the Japanese islands of Honshu
(central spine and northern half), Hokkaido and
Sakhalin. H. fulva and H. lilioasphodelus can be found wild
in parts of Europe, but it is unlikely that they are natives.
Where daylilies are indigenous, the climate is characterized by monsoonal, humid summers, with the rainfall
decreasing from south to north, and dry winters.
Botany
Daylilies are monocotyledons and mostly clump-forming,
sometimes rhizomatous perennials, making mounds of
leaves, from which arise usually branched scapes bearing
trumpet-shaped, lily-like flowers. Produced over a long
period from early to late summer, each flower only lasts
about a single day. The species flower colors are limited to
yellow, orange and fulvous shades, although the range has
been vastly extended by hybridizers over the past 75 years.
- The crown
- The junction point from which the leaves, flowers and
roots begin to grow is called the crown. If it becomes damaged, part or all of the plant will die. It should be planted to
lie approximately 1cm (1/2in) below soil level. It is the
crown, and the growth buds overwintering on it, that determine the frost hardiness of a daylily.
- The root system
- The roots of daylilies spring directly from the crown and
are generally pale tan-brown and thick, often with fleshy
swellings, though some also have fibrous roots. Springing
from the sides of the crown and growing outwards and
downwards, they may taper and be forked, like the claws of
a crab. They can be cylindrical as in H. dumortieri or spindle-shaped as in H. fulva, although those of H.
lilioasphodelus and H. middendorffii are relatively fibrous. Generally
the roots form dense, compact clumps, although H. lilioasphodelus and H. fulva increase freely by rhizomes. Hybrids
may be intermediate in root character.
The swollen organs on the roots act as food reservoirs,
carrying the plants through dormancy and enabling them
to grow away vigorously rather earlier in the spring than competing plants.
- The foliage
- The leaves of daylilies are strap-shaped, smooth to finely
ribbed, usually somewhat folded inwards along the midrib
and arise from the crown in two ranks, arching upwards
and outwards as they ascend to form a fan. Varying in
color from pale to dark green, they may possess a glaucous
bloom and are often yellowish to very pale green in spring,
sometimes assuming rich yellows and ochres in autumn.
H. aurantiaca, a warm climate plant, is the only
evergreen, the others being more or less winter dormant.
- The flower scapes
- The flowers of daylilies are borne on erect or oblique, usually rigid, scapes (leafless stems) that arise directly from the
leaf fan. Hollow and smooth, they range in color from
pale green to almost black, as in 'Sir Blackstem'. ln width
they can be as much as 5cm(2in) thick, as in 'Scapes from
Hell', or delicately slender, as in 'Kindly Light'.
Scapes vary in height from as little as 4cm (1 1/2 in), as in
H. darrowiana, to over 2m (6ft), as in H. altissima. The scapes of the hybrids range from 22-115cm
(9 -45in), averaging between 45-75cm (18-30in), but
reaching 1.2m (4ft) in some of those of Unusual Form.
They are more or less round in section and more or less
branched in their upper third. H. multiflora is notably
free-branching while H. dumortieri and H. middendorffi
branch only towards the tips. H. nana, by contrast, has
unbranched scapes and bears solitary flowers. If the plant is
transplanted or divided, the scapes are normally considerably lower than the registered height the following season.
Proliferations can sometimes produce scapes up to 10-12cm (4-5in) long and their own flowers
while still attached to the parent plant, as in 'Yesterday's
Memories' and 'Double Cutie'. This is more likely to apply to daylilies growing in hot climates.
- The bracts
- The bracts, situated on the upper third of the scape, are
usually held below the base of each branch, although they
occasionally appear at slight node-like swellings on the
scape. Resembling small, thin leaves, they are elongated oval, extending to a point, raised along the midrib and
vary from pale green to dark brownish-black. They usually shrivel after flowering.
- The flower buds
- The buds first appear small and almost round, gradually
elongating until they reach their maximum length on
opening. They also gradually swell above the tube, the tip
still pinched together, and are lightly ridged on the outer
surfaces. Ranging from light green to mahogany-brown, as in H. dumortieri, as anthesis approaches the buds assume
the final color of the sepals although they are flushed
green until fully open, particularly towards the tip.
- The flowers
-
The flowers of daylilies are large and colorful. The flower
is attached to the scape by a short pedicel and is made up of
six petal-like segments, known collectively as tepals. These
are arranged in two sets of three, the outer ones (initially
forming the casing of the flower bud) being called sepals,
the inner ones, petals. The sepals are usually narrower and
more pointed than the petals. The petals and sepals are
usually united towards the base, forming a short tube. The perianth is more or less trumpet-shaped in outline, flaring
only slightly in the species and early hybrids, but usually
recurving sharply or rolling back in the modern hybrids.
The reproductive organs arise from the throat or tube.
There are six slender stamens at the tips of which dangle
the anthers which produce pollen, the male reproductive
agent. The pistil, the female organ, is a single tube, rather
thicker and protruding further than the stamens, and arising from their midst. The end attached to the flower is
swollen and contains the ovules; the other end has the
slightly swollen stigma. When receptive, the stigma
becomes sticky so any pollen that touches it will adhere.
Fertilization takes place when the pollen grows down the
tube inside the pistil to reach the ovules. After fertilization
the flower falls away, leaving the ovary capsule to ripen.
- Fragrance
- Several species of daylily are noted for their fragrance, classified as musk or heavy and smelling like honeysuckle. The
fragrance of H. lilioasphodelus is considered the most powerful, closely followed by H. citrina and H. thunbergii. A
slight fragrance may also be detected in H. altissima,
H. dumortieri, H. middendorffi and H. minor. Humidity and
soil moisture are critical factors in the expression of fragrance in daylilies. In fragrant nocturnal daylilies the scent
is apparent upon opening, but in fragrant diurnals it does
not develop until the day has warmed up. In cooler climates far less fragrance is apparent in most daylilies.
- The seeds
- The seeds develop in the roughly egg-shaped, dark green
ovary capsules, which consist of six segments, separated by
six ribs. When ripe (60-80 days after fertilization), the segments spring open in pairs revealing three rows of round or
ovoid seeds, each with a slightly raised point at one end.
They are usually black and shiny if fertile, almost white if
sterile. The number of seeds in the capsule varies with the
species or cultivar, and is always fewer with tetraploids.
|
