Wednesday, January 28, 2015

Winter Flowers | Helleborus

Helleborus with its various different species  belongs to the buttercup (Ranunculaceae) family, along with other popular genera, such as clematis (Clematis), delphinium (Delphinium) and globeflower (Trollius).
There are two main groups of Helleborus. They are the caulescent and the acaulescent groups. The acaulescent species produces no stems while the caulescent species do produce stems. The rootstocks of these two groups are also different. The caulescent species cannot be produced from division.
The following list of Helleborus species, compiled by Joseph Woodward in 2006, contains information on which of the two main groups each species belongs to.
For more detailed information about any of the species listed, please click on the species name.
On this list H. abruzzicus and H. liguricus are described as species of their own. Furthermore H. bocconei, H. istriacus and H. hercegovinus are listed as independent species, which were observed as subspecies of H. multifidus in the past.
The Christmas Rose (H. niger) belongs to a group of its own. It produces no stems and might belong to the acaulescent species but H. niger differs from the other species of the Helleborastrum group, including all the acaulescent species except for H. thibetanus.

Helleborus x sternii

Hellebores are subdivided by Brian Mathew into six groups. The classification of the different groups is based on the following parameters:
- The presence of stems
- Carpels grown together at the base or not
- shape and texture of the anthers
- Size and shape of the seeds
- Ability of the plants to hybridize
- Differences of the leaves
- Colour of the flowers
 This leads to following classification:


Today we have hybrids that have risen from either natural or handmade crossings between different helleborus species.
The hybrids between acaulescent species sometimes lead to misunderstandings, because they are unfortunately described wrongly as H. orientalis. The correct description of these hybrids should be: H. x hybridus.
Caulescenten hybrids:
H. x ericsmithii: Hybrid of  H. x sternii and H. niger
H. x jourdanii: Hybride aus H. foetidus und H. viridis
- H. x lemonnierae: Kreuzungspartner unbekannt
H. x glandorfensis

Helleborus is a miraculous winter flowering plant. It joins the pansy, ornamental kale, camelia, berried shrubs and brilliant twigs like red osier dogwood as top choices to add to our gardens for winter color.

Kym Pokorny wrote a lovely article, "Hooked on Hellebores" in the November/December 2014 American Gardener magazine. She features Oregon Helleborus breeders, Ernie and Marietta O'Byrne and their accomplishments introducing new colors to the public.

Helleborus 'Shooting Stars'

Family | Ranunculaceae
Kreuter, Marie-Luise: Der Bio-Garten, BVL Verlagsgesellschaft mbH, München, 1981
Mathew, Brian: Hellebores, W S Cowell Ltd., Ipswich, 1989
Ahlburg, Marlene: Helleborus-Nieswurz, Schneerosen, Lenzrosen, Eugen Ulmer-Verlag, Stuttgart, 1989
Schiffner, Victor: Monographia Helleborum, Druck von E. Blochmann & Sohn in Dresden, Halle, 1890
Rice, Graham und Strangmann, Elizabeth: The Gardener`s Guide to Growing Hellebores, Timber Press, Inc., Portland, Oregon, 1994
Krausch, Heinz-Dieter: Kaiserkron und Päonien rot... Entdeckung und Einführung unserer Gartenblumen, Dölling und Galitz Verlag, Hamburg, 2003
Colston Burrell, C. und Knott Tyler, Judith: Hellebores, a comprehensive guide, Timber Press Inc., Portland, Oregon, 2006
Van Dijk, Hanneke und van Trier, Harry: Helleborus, Eugen Ulmer Verlag, Stuttgart, 2006
Rice, Graham: Helleborus, Octopus Publishing Group Limited, London, 2008
Becker, Christine: Helleborus in unseren Gärten - Christrose- lenzrose- Nieswürz- Der Vorfrühlingstraum, Pro Bussiness GmbH, Berlin, 2010
Becker, Christine: Helleborus-eine Monographie, Edition Veridit Art, Wendisch-Rambow, 2011
Becker, Christine: Helleborus 1485-1905, Viridi Art, Wendisch-Rambow, 2015

Specialized articles:
Werner, Klaus und Ebel, Friedrich: Zur Lebensgeschichte der Gattung Helleborus L. (Ranunculaceae), 1993, Flora (1994), 189, S.97-130
Further information: Articles of Will McLewin and Brian Mathew
McLewin and Mathew: "Hellebores: The first of a series of articles discussing the genus Helleborus", The New Plantsman 2 (2), Juni 1995, S.112-122.
McLewin and Mathew: "Helleborus croaticus", The hardy plant, Vol. 17, No. 1, 1995, S. 54-56
McLewin and Mathew: "Helleborus dumentorum: The structure of Hellebore Flowers and ist Implications", the New Plantsman 3(1), März 1996, S. 50-60
McLewin and Mathew: "Helleborus atrorubens: The Problem of Specification in Acaulescent Helleborus", The New Plantsman 3 (3), September 1996, S.170-177.
McLewin and Mathew: "Helleborus multifidus subsp. hercegovinus: Growth Idiosyncrasies of Hellebores", The New Plantsman 4 (1), März 1997, S. 44-50.
McLewin and Mathew: "Helleborus purpurascens", The New Plantsman 4(3), September 1997, S. 175-179.
McLewin and Mathew: "Helleborus orientalis and Helleborus x hybridus", The New Plantsman 5 (2), Juni 1998, S. 117-124.
McLewin and Mathew: Helleborus vesicarius und Helleborus thibetanus, The New Plantsman 6 (3), September 1999, S. 139-147
McLewin and Mathew: "Helleborus argutifolius, Helleborus lividus and Helleborus x sternii", The New Plantsman, Juni 2000, S.95-102.
McLewin and Mathew: "Helleborus viridis", The New Plantsman (3), September 2002, S.150-153.
McLewin, Mathew and Thomsen: "Helleborus bocconei and the Helleborus of Italy", Plantsman 5 (4), 2006, S.228-237.
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