Spontaneous Hybridization between Pinus mugo and Pinus sylvestris at the Lithuanian Seaside: A Morphological Survey
Table 2
Key-traits separating P. mugo spp. uncinata and P. sylvestris. An intermediate value of a trait was scored as 0.5. The weights were used in calculating of weighted score sum (WSS).
Trait (abbreviation)
WSS weight adult
WSS weight young
Typical P. mugo subsp. uncinata
Typical P. sylvestris
Score = 0
Score = 1
(1) Bark of the upper stem and main branches (BARK)
0.2
0.1
Fissured (small hard shells); grayish black
Peeling off in thin reddish brown flakes; dark brawn
(2) Needle colour (NEEDLE)
0.3
0.4
Fresh green
Blue green (glaucous)
(3) Cone apophysis (APOPH)
0.1
—
Hooked; blackish brown to brown; shiny
Flat; straw; dull;
(4) UMBO
0.05
—
Bordered by black or gray zone
Not bordered
(5) Symmetric cones (CONSYM)
0.05
—
No
Yes
(6) Tip of stem unit scale on the shoot bends backwards (TIPSU)
0.05
0.2
Yes
No
(6) Shoots of the previous year (SHOOT)
0.2
0.2
Grayish black; dark gray
Straw brawn
(7) Needle density on shoot (NDENSE)
0.05
0.1
High
Low
Needle anatomy (not used in WSS)
Index of stomata rows (ROWINDEX)
—
—
High
Low
Number of stomata (STOMEAN) (mean of the estimates in two rows)