RHODODENDRONRHODODENDRON

Genus: RhododendronGenus: RhododendronSpecies: Rhododendron degronianum

Subspecies: Rhododendron degronianum ssp. heptamerum

Varieties: Rhododendron degronianum ssp. heptamerum var.

hondoense

Cult. Varieties (CV): Rhododendron degronianum ssp. heptamerum var.

hondoense ‘Angel’

Genus: RhododendronGenus: RhododendronSubgenus: Hymenanthus

Section: pontica

Rhododendron degronianum ssp. heptamerum var.

hondoense

WAT is nu eigenlijk een soort?WAT is nu eigenlijk een soort?Helaas geen eenduidig concept maar verschillende

soortsconcepten.

Morphological species conceptMorphological species concept a species is a set of organisms that are similar and

that look different from other sets of organisms.

Biological species conceptBiological species concept The biological species concept defines a species as

members of populations that actually or potentially interbreed in nature

The Western meadowlark (left) and the Eastern meadowlark (right) appear to be identical, and their ranges overlap, but their distinct songs prevent interbreeding.

Biological species conceptBiological species concept

Phylogenetic species conceptPhylogenetic species concept

a species is a “tip” on a phylogeny, that is, the smallest set of organisms that share an ancestor and can be distinguished from other such sets.

Rhododendron species conceptRhododendron species concept species described and known only from cu1tivated material

have not been accepted unless they are very distinct (even then, the possibility that they are of accidental hybrid origin must be borne in mind).

species should differ from each other in at least two independent but correlatedly varying characters, and have geo- graphical or ecological distributions different from those of their closest allies.

S1 S2

Rhododendron species conceptRhododendron species concept if two (or more) taxa appear to intergrade, then the

resulting treatment depends on the proportion of intermediate specimens. If these are very few in number, two (or more) species are recognised, which a considered to hybridise to a small extent.

S1-2S1 S2

Rhododendron species conceptRhododendron species concept

Rhododendron species conceptRhododendron species concept If the proportion of intermediate specimens is larger (up

to c. 25% of the total), but the units are geographically discriminate with the morphological intermediates in geographically intermediate area, then one species is recognised with two (or more) subspecies within it.

S1 ssp.a S1 ssp.b

a x b

Rhododendron species conceptRhododendron species concept if the various units are geographically indiscriminate,

then one species is recognised, eiter undivided, or if the morphological variation is appropriate, divided in two (or more) varieties.

Rhododendron species conceptRhododendron species concept

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Niet zo! http://www.rhododendron.dk/rhodo.htm

Hoe determineren?Hoe determineren? Welke soort is dit???

Hybride met catawbiense/maximum

Hoe determineren?Hoe determineren? Herkomst? Zaad / stek? Welke literatuur? Volwassen materiaal gebruiken bloem en vruchten….dus herbarium maken!

Hybride met catawbiense/maximum

Hoe determineren?Hoe determineren? Sleutel:

Hybride met catawbiense/maximum

Hoe determineren?Hoe determineren? Sleutel:

Hybride met catawbiense/maximum