Saturday, May 28, 2016

Rhododendron worlds

Rhododendron 'Aprilmorgen'. Picture taken between rain showers on an April morning in 2016.
Each year, in April and May, Bremen's Rhododendron Park lets people dive into a colorful sea of blooms displayed by rhododendrons and azaleas from around the world. Before getting intoxicated by the rhododendron fragrance scenting the air over the many paths between the cultivated plants, I always like to walk to the rhododendron globe, a sculpture indicating the distribution of rhododendron species by numbers laid onto subcontinents, islands and rhododendron-rich regions.
Rhododendron-globe sculpture in Bremen's Rhododendron Park

Terra Europa on rhododendron-globe sculpture
On the Pacific Ocean section of the globe relief, seen in the picture above, the following text is written: Verbreitung der Rhododendron auf der Erde - In der Natur kommen etwa 1000 Arten - Species - vor. In English: Distribution of rhododendron species on Earth - There are about 1000 naturally occurring species. I never added up all the laid-on numbers. Occassionally, I pick a region I am just interested in and check its rhododendron-species-number to get an idea of how the region is doing rhododendron-wise. The numbers in the picture above give a count of four species for central Europe and five for the Caucasus region. Step clockwise around the globe to face North America: three species in the Northeast, four in the Appalachian Mountains, fifteen in the Subtropical East, four in the Northwest and three in Alaska. Japan: 41. By far the largest counts are found within the Southeast-Asia regions that cover the Himalaya, China and areas further south. At a glance, I get a sum of over 700 species there. The high density of large counts given for this area is consistent with the biogeographical recognition of the Sino-Himalayan area as the center of rhododendron diversification. Rhododendron rubiginosum is one of those species growing over a wide area of China and northeast Myanmar (Burma).
Inflorescence of Rhododendron rubiginosum
In nature, rhododendrons grow from sea level to high-elevation mountain habitats. The impressive flowering shrubs—from small to giant—are found in coastal or alpine woodlands, temperate rain forests and tropical environments. And many of them thrive in Bremen's climate—inside and around the Rhdodendron Park [1-3].

The ability of rhododendrons to resist cold differs from one species to another. As a result of horticultural nursing and research, ornamental rhododendrons with various degrees of winter hardiness now exist. Further, variations in flower color, size and shape have been realized in hybrid rhododendrons. For example, the Rhododendron 'Aprilmorgen' (April morning, see top picture) is a hybrid with pink flower buds, which open up as pink-white flowers that eventually turn completely white.

The Rhododendron 'Aprilmorgen' was introduced by the nursery Baumschule H. Hachmann in 2004 [4]. It is a Yakushimanum hybride, named after the Japanese Island of Yakushima, where the purebred plant, Rh. yakushimanum, grows in mountain areas at an elevation ranging from 1200 to 1800 m (3600 to 5400 feet). An information panel in the park with the title Und noch mehr Yakushimamum-Rhododendron (Yet more Yakushimanum-Rhododendron) explains that this species is favored in deriving hybrids, because it has a compact growth, rich flower display and excellent winter hardiness.

Getting to the Rhododendron Park
Take the tram from a downtown stop: BSAG Line 4 towards Borgfeld/Lilienthal. Exit at the Bürgergmeister-Spitta-Allee stop. You'll find yourself in the middle section of Schwachhauser Heerstraße. Use the pedestrian traffic signal to cross over to the south side of the street, turn left and cross Bürgergmeister-Spitta-Allee at the signal. Continue walking eastbound and turn right on Marcusallee. Continue on this street to its intersection with Deliusweg. Here you may either want to turn left and head to the Botanika (the “Green Science Center” [3]) and Botanical Garden section of the park or continue along Marcusallee until you arrive at the left-side semicircle, the main entrance (Haupteingang, see map below) of the Rhododendron Park. Note that there also is a bus option, Line 20, to get from the Bürgergmeister-Spitta-Allee/Schwachhauser Heerstraße junction to the main entrance.

The park is open from sunrise to sunset. Admission is free. Guided group tours are available.

Map of Bremen's Rhododendron Park
Keywords: travel, Germany, Bremen, rhododendrons, heather family, Ericaceae.

References and more to explore
[1] Bremen Tourism: Rhododendron Park [].
[2] Jon M. Valigorsky: Rhododendrons of North Germany. Journal American Rhododendron Society Fall 1986, 40 (4). EJournal access:
[3] Botanika Bremen:
[4] Deutsche Genbank Rhododendron: Rhododendron 'Aprilmorgen', Hans Hachmann (1998)[].

Grammar comment: On the rhododendron globe it says Verbreitung der Rhododendron auf der Erde. I would instinctively say Verbreitung der Rhododendren auf der Erde. Is it wright either way?

Further walking tours in Bremen

No comments: