Quercus- Oak Flashcards
Quercus
Oak
Oak trees
generally large, round headed, very long-lived trees
Quercus macrocarpa
Bur oak
Bur oak
most common one grown here
medium sized tree (15-20 m)
most often single trunk medium headed
common street, park and private yard tree
not high maintenance, unique leaf, nice autumn colour, not overly large for yard
Bur oak- buds
alternate buds
bur oak- leaves
leaves simple, variable in shape
middle of leaf has deepest sinus, almost to the mid-rib; short petiole unique
cuneat (wedge shaped) at base
commonly darker green/shiny green on top of leaf and lighter green on underside
Bur oak- monoecious
female flowers solitary or multi-nut spike; produce the nut (acorn)
staminate flowers produce pollen; male flowers on pendulous catkins
mossy cup oak- because of the hairy ring around the top of the cup; about half the acorn is exposed unique
Bur oak- branches/bark
Stout short branches; yellowish-brown and hairy when young becoming corky (ridges), gnarled and hairless with age;
bark becomes deeply furrowed with age
gets more corky and deeply ridged as time goes on
Bur oak- colouration
bronzy yellow autumn colouration; antique bronze
Bur oak- pests
bulletgall wasp
Bulletgall wasp
a common pest; two year lifecycle, involving one year on leaf and one year in stem
galls do not kill branch-they do restrict growth; unsightly in eyes of homeowner
cosmetic- ugly and weird
see this and you know it is a bur oak
Two types of galls
vein gall leads to round hard galls on stems (more concerning)
small round gall no stem gall
Quercus ellipsoidalis
Northern Pin oak
Northern pin oka
starting to pick up in popularity
not very popular yet
very showy in autumn, red colour
can be grown here
North Pin oak- nut
no mossy cup
1/3 of nut enclosed in cup (smaller acorn and more exposed)
not fuzzy
