AGEH 28, Fall 2013
Shasta College Arboretum
Fraxinus latifolia, Oregon ash
olive family, Oleaceae
Fraxinus latifolia, Oregon ash
olive family, Oleaceae
• Deciduous tree to 40-80 x 30-50 ft; native to
Sierra Nevada, and N. Calif to BC
• ID: Lvs 6-12 ”, 5-7 leaflets, end leaflet larger
than side ones; tree dioecious (sexes on
separate plants); fruit a flat samara with a
terminal wing, hanging in clusters
• Care: Sun, no irrigation when established;
tolerates standing water in winter
• Value: fall color!!
• Problems: leaf spot fungi even on healthy plants,
heart rot on older trees, various insects
Nyssa sylvatica, sourgum, tupelo;
Nyssa family, Nyssaceae
Nyssa sylvatica, Sourgum, tupelo
Nyssa sylvatica, Sourgum, tupelo,
Nyssa family (Nyssaceae)
• Native to eastern US; 30-50 x
15-25 ft
• Likes moist deep soil, will
tolerate some drought, takes
poorly drained, heavy soils
• Excellent shade tree; fruit
sour, but attractive to birds;
good fall color even in mild
winter climates
• Fruit a drupe (like olive)
Albizia julibrissin,
silk tree, “mimosa”
Pea family, Fabaceae
Albizia (Albizzia) julibrissin,
silk tree, “mimosa”
• Native to Asia
• ID: Tree to 40 ft, twice as wide as high
Leaves 2x pinnate,
Flowers powder-puff, ‘Rosea’ has richer pink
• Value: Likes high summer heat; tolerates low
water; makes shade; flowers fragrant, attract
bees and hummingbirds
• Problems: somewhat invasive in
moist places; a bit messy,
Euonymus alatus,
winged burning bush
Euonymus alatus,
winged burning bush
FALL
COLOR!!
Euonymus alatus,
winged burning bush
• Native to northern Asia; needs moderate water
• ID: leaves opposite, oval, 2 in., twigs usually with
corky wings
• Tolerates full shade, but best color in sun or part
shade
• Species plants can be large (20 ft); buy compact
forms ‘Compacta’, etc.; good against dark
evergreens (brick walls???)
Invasive in wildlands where there is summer rain
(by seeds)
Hibiscus syriacus, rose of sharon
Hibiscus syriacus, rose of sharon
• Deciduous shrub from E. Asia
• 10-12 x 6-12 ft.; can be trained as small tree,
espalier
• Likes heat, needs sun and moderate water to
bloom well
Hibiscus syriacus, rose of sharon
• Can seed around; buy good forms (sterile
triploids: Aphrodite, Diana, Helene, Minerva);
• For larger flowers, cut back last season’s growth
to 2 buds
Populus nigra ‘Italica’,
Lombardy poplar
Populus nigra ‘Italica’,
Lombardy poplar
• Native to Europe; grows 50-100 x 10-30 ft.
• ID: tall and narrow; leaf slightly diamond-shaped
at base, narrowed to long tip, serrate
• Value: Fast and tough; good for hot
summer/cold winter climates; yellow fall color;
dramatic in the landscape; wooden shoes
• Problems: suckers profusely, heaves, clogs
sewer pipes
Populus nigra ‘Italica’,
Lombardy poplar
• Forms: ‘Italica’ is a male form, no seeds; female
poplars produce lots of cottony fruit
Syringa vulgaris, common lilac
ID: shrub, to 20 x 20 ft; leaf heart-shaped
(cordate); fragrant flowers
Syringa vulgaris, common lilac
• Native to E. Europe
• Needs: sun/ part shade; some
water; winter chill, neutral to
alkaline soil (add lime if needed)
• Care: Must prune just after
flowering (you have a week,
maybe); also, prune out a few of
the oldest stems each year to
encourage new growth
• Forms: Zillions (hundreds) of
varieties
Salix babylonica, weeping willow
Salix babylonica, weeping willow
• Tolerates poor drainage
• Large tree (50 ft high and wide),
rather short-lived, with weak
wood; not suitable for city lots
• Largely replaced in gardens by S.
x sepulcralis ‘Chrysocoma’; there
are also other better forms for this
same look.
Taxodium distichum, swamp cypress
Taxodium distichum, swamp cypress
Taxodium distichum, swamp cypress
• Native to southeastern US
• 100 ft in the wild, but garden
trees 50-70 x 20-30 ft.
• Very tough, tolerant, deciduous
conifers of great size, with
shaggy bark and graceful sprays
of needlelike leaves. Takes
waterlogged or dry soils; good
for streambank or lake edge.
Metasequoia glyptostroboides,
dawn redwood
Metasequoia glyptostroboides,
dawn redwood
• Native to China; thought to be extinct
for millions of years but found again in
1940s.
• Deciduous conifer. Fast growth when
young, to a pyramid-shaped adult of
90 x 20 ft. Likes moisture, so grows in
lawns, but surface roots lift turf
eventually. Winter form sometimes
gawky.
• Resists oak root fungus.
Dawn redwood vs. swamp cypress
Dawn redwood vs. swamp cypress
Cornus stolonifera, redtwig
dogwood & yellowtwig dogwood
C. s. ‘Arctic Fire’
C. s. ‘Flaviramea’
Cornus stolonifera, redtwig
dogwood & yellowtwig dogwood
Native to n. Cal and north to Alaska
ID: multistem shrub 7-9 x 12 ft.
Spreads via underground stems and
rooting branches
Leaves 1.5 – 2.5 in, oval, deep
green; flrs small, white, in clusters;
fruits white or bluish
Value: 4 Fs, esp. red or orange fall
color, and red or yellow winter twigs
Cornus stolonifera, redtwig
dogwood & yellowtwig dogwood
• Care: sun to part shade, regular
water (streamside plant in the wild);
cut back SEVERELY in late
dormant season
• Use: thrives in coldest mountains,
even in valleys of S. Cal, useful for
streambanks, property boundaries,
screen
• Names: aka red osier dogwood;
Cornus sericea very similar
Forsythia x intermedia,
forsythia
Forsythia x intermedia,
forsythia
Origin: China, olive family
ID: 4-petal yellow flowers, vase-shaped or
arching shrub; leaves oval with pointed tip,
serrate; bark with lenticels
Forsythia x intermedia,
forsythia
• Value: yellow flowers in early
spring; tough; very cold hardy;
can be forced by picking stems in
bud
• Care: sun, moderate water; prune
1/3 of oldest branches to ground
each year
• Forms: get good ones!
Sophora japonica, “popbead tree”
J. pagoda tree, Ch. scholar tree
Sophora japonica, “popbead tree”
J. pagoda tree, Ch. scholar tree
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Native to China, Korea, Japan
60 ft high, 2/3 as wide
Use for park, shade
Leaves compound, alternate
Flowers pea-flower-shaped, white,
bloom in summer (August)
• One of the 50 fundamental herbs
used in traditional Chinese
medicine
• (aka Styphnolobium japonicum)
Symphoricarpos x chenaultii,
coralberry
Symphoricarpos x chenaultii,
coralberry
• Native to North America; this form is a hybrid
of S. orbiculatus from eastern US.
• To about 6 ft; best used as a wild thicket for
erosion control on steep banks, spreads by
root suckers; needs part to full shade in hot
climates.
• Cut stems nice for winter arrangements.
• There is a one-foot dwarf ‘Hancock’ valued
as woodland groundcover.
Alnus cordata, Italian alder
Alnus cordata, Italian alder
• Native to Italy and Corsica
• ID: 40 x 25 ft.; growth vertical when
young; leaf heart-shaped, 4 in.,
glossy rich green; flrs = male soft
catkins and female woody catkins
(“cones”)
• Value: good near creeks, fast
growth, flrs good display before lvs;
favored in the SW
• “More restrained than A.
rhombifolia.”
• White alder is our native tall alder
Liriodendron tulipifera, tulip tree
magnolia family--Magnoliaceae
Liriodendron tulipifera, tulip tree
• Native to eastern United States
• Tallest deciduous tree in the
world—200+ ft. in the wild
• Yellow fall color, even in S. Calif.
Liriodendron tulipifera, tulip tree
• Flowers not showy, as
carried high on tree; but
beautiful up close. Starts
blooming when 12-15 years
old
• Likes deep rich soil, roots
shallow so cannot garden
under them
• Susceptible to Ganoderma
root/butt rot fungus.
Liriodendron tulipifera, tulip tree
Because of its tall, straight trunk
and wood that is soft, lightweight,
straight-grained, resistant to
splitting, and easily worked, Native
Americans and early pioneers
frequently hollowed out a single
log to make a long dugout canoe.
Its wood is sold commercially as
“yellow poplar,” & used for
furniture, musical instruments,
interior finishes, shingles, & boats.
Liriodendron tulipifera, tulip tree
• ID—tall straight growth, 4-lobed
leaves like no other.
• ‘tulipfera’ means ‘tulip bearing’
Magnolia family (Magnoliaceae)
Ancient flowering plant group; some of the
earliest fossil flowers found look like
magnolias
Magnolia x soulangeana ‘Rustica
Rubra’; RR saucer magnolia
More pix
Magnolia x soulangeana
‘Rustica Rubra’ Saucer Magnolia
10-25 x 10-15 ft;
Value: spectacular bloom in
deep pink before leaves; this
form with spectacular fruits
(pendent, rose pink, with red
“seeds”) attractive to birds
Hybrid of M. denudata and M.
liliiflora
Magnolia x soulangeana
‘Rustica Rubra’ Saucer Magnolia
Fruit a follicle, shaped like misshapen sausage
from side; this is a view from below
What’s a follicle?
A follicle is a dry fruit,
developing from a single pistil,
opening along one side;
magnolia fruit is an aggregate
of follicles
(this magnolia fruit is typical of
bull bay magnolia, not typical of
saucer magnolia)
Wistaria sinensis, Chinese wisteria
Wistaria sinensis, Chinese wisteria
• VIGOROUS vine, beautiful but
messy
• Invasive into moist areas
• Most common wisteria in West
• Leaves with 9-13 leaflets
• Notice the direction of twining for
ID: Counterclockwise= W.
sinensis; Clockwise= W.
floribunda
• Plant toxic (esp seeds)
• Prune in winter
Celtis australis
hackberry
Celtis australis
hackberry
Lagerstroemia indica
Crape Myrtle
Lagerstroemia indica
Crape Myrtle
• Colorful and long
lasting flowers
• Blooms in the
summer and autumn
• Panicles of crinkled
flowers with crepe-like
texture
Lagerstroemia indica
Crape Myrtle
• Bark shed throughout
the year
Lagerstroemia indica
Crape Myrtle
• From China and
Korea
• Huge variety of
cultivars
• Best in mild climates
that are not overly
humid such as inland
California and Texas
Crataegus phaenopyrum
Washington Hawthorn
Crategus phaenopyrum
Washington Hawthorn
• White to red flowers
• Dense growth
• Menacing thorns can
make an inpenetrable
hedge
Crategus phaenopyrum
Washington Hawthorn
• Red pea-sized fruits
are relished by birds.
• Can be cooked into
jellies and jams.
Malus zumi
Radiant Crabapple
Malus zumi
Radiant Crabapple
• Many different
cultivars
• Hardier and more
tolerant of wet soil
than other stonefruit
• Most useful and least
troublesome of
flowering trees
• They can tolerate the
heat
Spiraea japonica
Goldflame
Spiraea japonica
Glodflame
• New growth is
bronze-red turning
bright yellow, then
eventually mid-green
• Dark pink flowers
produced mid to late
summer
• Easy to grow
• Enjoys sunny spot in
moist well-drained soil