Rhododendron macgregoriae
Rhododendron macgregoriae
at the Rhododendron Species Foundation (1983-074)
The story of Rhododendron macgregoriae
begins in 1890 when a Mr. Belford, accompanying Sir William
MacGregor on the first recorded ascent to the highest summit
of the Owen Stanley Range, first collected specimens of a
new species of Rhododendron at 3350m on Mount Yule
in New Guinea. Dried material was sent to Baron Ferdinand
von Mueller, Government Botanist in Victoria, Australia, who
the following year published a description of the plant in
the Journal of Botany (J.Bot. 29: 177), naming it for Lady
MacGregor, wife of Sir William MacGregor, the first Lieutenant-Governor
of New Guinea. It was to be another 65 years, however, before
Rhododendron macgregoriae would be introduced into
cultivation when, in 1955, wild collected seed was distributed
by the Rijksherbarium at Leiden in The Netherlands.
Rhododendron macgregoriae - yellow form
The geographical distribution of Rhododendron
macgregoriae is limited to New Guinea although the species
is widespread across the whole island growing from only 500m
up to 3350m altitude, preferring open sites in mossy forest
or grassland.
In "Rhododendrons of Subgenus Vireya",
Dr. George Argent classifies Rhododendron macgregoriae
in section Euvireya and describes the species as a terrestrial
shrub or small tree growing to 5m in height, bearing leaves
elliptic to ovate in shape of up to 14cm in length by 5cm
across.
Rhododendron macgregoriae
The flowers of Rhododendron macgregoriae
are shortly tubular in shape, the corollas 2.5cm in length
and up to 3cm across the extended lobes, carried in umbels
of between generally 7 and 15 flowers. Flower colour is quite
variable with yellow, orange, red and pink forms having been
recorded, some with a contrasting central "eye"
of orange or yellow. The yellow and orange forms are more
common, especially in cultivation, whilst the red and pink
forms are rarely seen in Papua New Guinea, tending to occur
more frequently on the western side of the island of New Guinea.
Rhododendron macgregoriae
at the Royal Botanic Garden Kew
In New Guinea, plants of Rhododendron
macgregoriae growing at low elevations in areas under
cultivation by the local inhabitants are considered to be
weeds and also known as poisonous to grazing livestock. This
toxicity is harnessed by the villagers in dealing with any
local rat populations by mixing the flowers with sweet potato
to make an effective bait.
Rhododendron macgregoriae x Rhododendron inconspicuum
at the Royal Botanic Garden Edinburgh
Rhododendron macgregoriae is believed
to be pollinated by butterflies and indeed hybridises freely
in the wild, principally with Rhododendron zoelleri,
R. dielsianum and R. inconspicuum. Two hybrids
with the latter species, grown from wild collected seed, are
pictured (above and bottom). One, R. macgregoriae
x R. inconspicuum, is light pink with a creamy yellow
eye, whilst the other, the reverse cross, is a darker shade
of pink and considered of sufficient merit to be named and
registered as Rhododendron 'Sweet Mac'.
A selection of hybrids using
Rhododendron macgregoriae
as the seed parent. |
Rhododendron
'Yellow Ball'
R.macgregoriae x R.retivenium
|
Rhododendron
'Mountain Flame'
R.macgregoriae x R.stenophyllum
|
Rhododendron
'Little Bo Peep'
R.macgregoriae x R.anagalliflorum
|
Rhododendron
'Popcorn'
R.macgregoriae x R.loranthiflorum
|
Rhododendron
'Coral Chance'
R.macgregoriae x R.commonae
|
Widely grown by Vireya enthusiasts around
the world, Rhododendron macgregoriae is generally
considered one of the easiest species to grow and flower in
cultivation and has also proved to be a popular choice of
parent with hybridisers. Today, nearly one
hundred named cultivars are of "mac" descent,
many of them retaining the distinctive appeal of this parent
together with its reliable, free-flowering habit. A selection
of photographs of hybrids produced using Rhododendron
macgregoriae as either seed parent (above) or pollen
parent (below) illustrates the range of colour and form now
available to growers.
A selection of hybrids using
Rhododendron macgregoriae
as the pollen parent. |
Rhododendron
'Sunny'
R. christianae x R.macgregoriae
|
Rhododendron
'Flamenco Dancer'
R.aurigeranum x R.macgregoriae
|
Rhododendron
'Rob's Favourite'
R.lochiae x R.macgregoriae
|
Rhododendron
'Sweet Mac'
R.inconspicuum x R.macgregoriae
A natural hybrid raised from wild collected seed.
|
Rhododendron
'Orangemaid'
R.laetum x R.macgregoriae
|
|