Helleborus niger L.

Humidity Value H

1

very dry

1⁺

dry

2

moderatly dry

2⁺

moist

3

medium wet

3⁺

wet

4

very wet

4⁺

soggy

5

submerged or underwater

f

plants living in running water

u

mostly submerged plants

v

partly submerged, partly floating plants

w

humidity moderately variable (± scale of 1-2)

w⁺

highly variable humidity (scale exceeding ± 2)

Reaction Value R

1

Very acid (pH 2.5-5.5)

2

acid (pH 3.5-6.5)

3

lightly acid to neutral (pH 4.5-7.5)

4

neutral to basic (pH 5.5-8.5)

5

basic (pH 6-5 -> 8.5

Nutriments value N

1

very low in nutrients

2

low in nutriments

3

medium-poor to medium-rich in nutrients

4

rich in nutriments

5

very rich in nutriments

Salinity tolerance

1

halotolerant

3

halophyle

Light Value L

1

very shady

2

shady

3

lighted areas

4

luminous

5

highly luminous

Temperature factor T

1

alpine to nival stages (from the treeline to the snowline)

1⁺

suprasubalpine and upper subalpine levels (pine and larch forests)

2

subalpine level (coniferous forests without beeches up to the upper limit of spruces)

2⁺

lower subalpine and upper mountain stages

3

mountain level (beech and silver fir forests, in the central Alps Scots pine forests)

3⁺

lower mountain and upper hill levels

4

hill level (mixed deciduous oak forests)

4⁺

hot places, hill level

5

very hot places, hill level (only in the hottest places, typical of southern Europe)

Continentality K

1

Atlantic (high air humidity, very low temperature variations, mild winters)

2

Sub-Atlantic (high air humidity, low temperature variations, relatively mild winters)

3

sub-Atlantic to subcontinental (average air humidity, moderately variable temperature, slightly low winter temperatures)

4

subcontinental (low air humidity, large temperature variations, rather cold winters)

5

continental (very low air humidity, very large temperature variations, cold winters)

EX

Extinct

RE

Regionally Extinct

CR(PE)

Critically Endangered, Probably Extinct

CR

Critically Endangered

EN

Endangered

VU

Vulnerable

NT

Near Threatened

LC

Least Concern

DD

Data Deficient

NE

Not Evaluated

NA

Not Applicable