Week 3

1
Week 3

• Plant Group 1
• Large Deciduous Trees

2
Acer negundo Box Elder
Location Find along woodland edges Glaucous
twigs, trifoliate or pinnately compound leaves
unusual for Acer Milky sap from broken petioles
like Norway maple. Dioecious females are
heavily fruiting leading to weediness There are
some cultivars for variegation and fall color I
would avoid
3
Carya ovata Shagbark Hickory
Location NW of Curtiss Hall or East of
Bessey Large odd-pinnately compound leaves,
large buds with loose scales, heart shaped leaf
scar Mature trees develop wonderful shaggy
bark Fruits split and release nuts while still
attached to tree Transplanting can be difficult
because of deep taproots Golden yellow fall color
4
Carya cordiformis Bitternut Hickory
Location NW of Curtis Hall or NW corner of
Library Sulfur yellow buds! Heart shaped leaf
scar Pinnately compound leaves smaller than
shagbark hickory Reliable golden yellow fall
color. This hickory is a nice replacement for
green ash. Fruits also split on the
tree
5
Celtis occidentalis Common Hackberry
Location South of Horticulture Hall Like elm it
has oblique leaf bases, vase shape form. Fruits
are not like elm drupes, not samaras Buds
appressed to the stem Warty/blocky bark Tolerates
tough conditions, but is not a first rate tree
because of nipple gall, insect problems, and
tendency to break in storms
6
Fagus grandiflolia American Beech
Location West side off the Knoll Long, narrow,
sharply pointed, divergent buds! Fruit is
3-winged nut in a spiky covering Glossy serrated
leaves, smooth gray bark Not flood tolerant, has
shallow roots, and branches often touch the
ground
7
Fraxinus pennsylvanica - Green Ash
Location In between Horticulture Hall and Bessey
Hall
May be the most common landscape tree in the
Midwest Emerald Ash Borer has already lead to its
demise in other states, and time will tell when
the borer reaches Iowa. Weak wooded, females
produced lots of messy fruit (samaras) Glossy
pinnately compound leaves Yellow fall color and
diamond patterned bark
8
Ginkgo biloba Ginkgo
Location West of Catt Hall Fan shaped
(dichotomous) leaves Leaves are alternate or
whorled, arising from a short spur (compressed
shoot) Gymnosperm produces seeds, not fruits
messy and smelly when they fall and ripen
Develops yellow fall color almost overnight Tough
tree that has been around since the Jurassic
period!
9
Juglans nigra Black Walnut
Location North of Music Hall in
woods Distinctive buds pale and
silky/downy Chambered pith Pinnately compound
leaves with many leaflets Leaves omit odor when
crushed Allelopathic Leaf scar is notched at top
10
Liquidambar styraciflua American Sweetgum
Location In Kildee Hall courtyard and large tree
north of Lagomarcino Hall Alternate, star-shaped
leaves, usually with 5 acuminate lobes Fruit is a
syncarp of dehiscent capsules Terminal buds ¼ to
½ inch long Common in southeastern U.S., where it
is seen as undesirable Marginally hardy in
central Iowa Bright fall color rarely develops
here because of early frost
11
Maclura pomifera Osage Orange
Location Across from football practice facility
Beach Ave. and Friley Rd. Intersection Alternat
e, leaves with acuminate leaf tips Stems with
stout axillary thorns Fruit is a 4-6 globose
syncarp of drupes Orangey colored under-bark
often visible on older trees Bark on older trees
has irregular vertical fissures and ridges Not
native to southern Iowa, but is considered
naturalized
12
Morus alba White Mulberry
Location Growing as a weed in most planting beds
around campus Dimorphic leaves (some undivided,
some divided) Leaf base can be rounded or
cordate, and all leaves have coarsely-serrated
margins Greenish-yellow twigs Clusters of drupes
in summer look similar to raspberries Introduced
for silkworm food Has become naturalized in the
U.S. No fall color, as leaves drop with first
hard frost
13
Populus alba White Poplar
Location SW corner of Lake LaVerne Alternate
leaves are green above, silvery-white
beneath Leaves are maple-like in appearance and
3-lobed Petioles and twigs are covered with white
hairs Suckers freely from roots Undesirable
break in storms, have diseases
14
Populus deltoides Eastern Cottonwood
Location Southeast of Rec. Center Alternate
leaves are broadly triangular in
appearance Petioles are FLAT Tips of branches are
green with fleshy terminal buds Fast growing tree
native to wetter soils Messy, sheds seeds with
silky white hairs (cotton) Can grow very large,
up to 75-100 or taller Fall color is poor yellow
Flood Tolerant!
15
Prunus serotina Black Cherry
Location In between Gilman and Physics
Hall Alternate leaves are oblong-ovate and
acuminate Fine serrations on leaf margins
(serrulate) Glands on petiole below leaf
blade Bark is gray-black and scaly or flakey in
appearance Good for wildlife (birds), but fruits
can be messy! Like many Prunus, this species
suffers from diseases
16
Quercus bicolor Swamp White Oak
Location South of Horticulture Hall Leaves less
lobed than white oak. Also not as lobed as bur
oak and acorns are less hairy Leaves are dark
green above and white beneath Fast growing oak
that is flood/drought tolerant Columnar form when
young, but spreads with age Can have
yellow/orange fall color
17
Quercus macrocarpa Bur Oak
Location South of Catt Hall Stout twigs, acorns
are covered with a hairy cap Leaves are large and
sinuses are deep at the base and shallow at the
tip (fiddle-like appearance) Tolerant of our high
pH, slow growing, brown/orange fall color Native
prairie species resistant to fire
18
Quercus robur English Oak
Location North of Curtiss on each side of
sidewalk. Largest English Oak in Iowa is on west
Side of LeBaron Hall Like the other oaks, this
species has clustered terminal buds Auricles at
leaf base, rounded lobes, sinus not as deep as
white oak Longest acorns of all the oaks we
study Marginally hardy here, will sometimes see
tip dieback Columnar cultivars are popular
19
Quercus muehlenbergii Chinkapin Oak
Location Right west of Honors hanging over the
sidewalk Lasagna-noodle like leaves, does well
in our high pH soils One of the best performing
oaks we have and deserves more use Young trees
grow fast and have very nice form
20
Salix alba White Willow
Location Across from Hilton along Squaw
Creek Also known as weeping willow Lanceolate
leaves with white undersides Pointy buds are
appressed (held tightly to stem) Loves water and
is best kept around ponds, lakes, or streams It
is weak-wooded and sheds branches in storms
21
Ulmus pumila Siberian Elm
Location East of Forker Building Alternately-arr
anged leaves are similar to American elm in
appearance, but smaller Oblique leaf bases Buds
are basketball shaped Weedy, produces many
seedlings Not highly valued, considered to be a
trashy tree with poor form