September Color Appears at the Washington Park Arboretum

September 23rd, 2013 by Pat Chinn-Sloan

Keystone Species of New Zealand

Keystone species of New Zealand (September 9 - 22, 2013)

               Keystone Species of New Zealand                     (September 9 – 22, 2013)

1)   Nothofagus menziesii   (Silver Beech, Tāwhai)

  • Natural range: endemic to New Zealand.  Found throughout South Island.
  • Trunk is silvery-gray and has horizontal lines (lenticels).
  • Dark-green, oval leaves are glossy and have toothed edges.
  • Largest specimen was transplanted in Autumn 2012 with help from a very large crane.

2)   Nothofagus solandri var. cliffortioides (Mountain Beech, Tawhairauriki)

  • Deep green, oval leaves have a pointed tip and rolled edges.
  • Grows in lowland mountain regions to about 65 feet.  At high altitudes, it forms a “goblin forest” where the trees are no more than 6 feet tall.
  • Two large specimens transplanted with crane in Autumn 2012.

3)   Griselinia littoralis   (New Zealand Broadleaf, Kapuka)

  • Found throughout most of New Zealand from sea level to 3000 feet.
  • Deep green, oval leaves are thick and very shiny, and this fast-growing plant is often used for hedging and shelter planting.
  • Species name ‘littoralis’ means “growing by the sea”, indicating tolerance of salt spray.

4)   Chionochloa rigida   (Narrow-leaved Snow Tussock), C. rubra  (Red Tussock)

  • Genus of Chionochloa, comprises of about 20 species – all but one are native to New Zealand.
  • Despite its name, C. rigida has a flowing habit reaching 3 feet with flowering stems reaching 5 feet.  Leaves dry out giving the plant an overall golden color.
  • C. rubra has reddish colorings with fine weeping leaves reaching 3 to 4 feet and flowering stems that rise just above the foliage.

5)   Phormium colensoi  (syn. P. cookianum) and P. tenax  (New Zealand Flax, Wharariki)

  • Both species native to New Zealand, P. colensoi is endemic;  both are widespread.
  • P. colensoi seed pods tilt downwards and twist in a spiral as they dry.  P. tenax seeds are held upright and do not twist when drying.
  • P. tenax is a larger plant with leaves reaching 9 feet and flowering stalk up to 15 feet compared to P. colensoi whose leaves reach 5 feet and flowering stalk is slightly taller at 6 feet.

September Color Appears at the Washington Park Arboretum

September 2nd, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (August 26 - September 8, 2013)

Selected cuttings from the Washington Park Arboretum (August 26 – September 8, 2013)


1)  Betulaceae          Carpinus japonica, Corylus colurna, Ostrya carpinifolia

  • Nut-bearing, often enclosed in interesting husks, cones or bracts.

2)  Fabaceae            Colutea orientalis

  • Legumes, which are dry fruit in pods that dehisce (open along a seam).

3)  Gunneraceae         Gunnera manicata

  • The fruit-bearing conical spike can reach 6 feet in length.

4)  Magnoliaceae        Magnolia grandiflora, M. officinalis var. biloba, M. sieboldii

  • Cone-like fruits, from green to red, open to display bright orange seeds.

5)  Myricaceae          Morella californica

  • The fruit is a drupe with a waxy coating that can be used to make candles.

6)  Myrtaceae           Callistemon sieberi

  • Bottlebrush seed capsules remain unopened until stimulated by fire.

7)  Paeoniaceae         Paeonia rockii, P. suffruticosa

  • Peony fruit pods will open when ripe to display black or bright red seeds.

8)  Proteaceae          Grevillea victoriae

  • The profusion of colorful fruit on this shrub outshines many flowering plants nearby.

9)  Rosaceae            Rosa corymbulosa, R. davidii, R. roxburghii, Sorbus splendida

  • Rosaceous fruit can be drupes, achenes, nuts, follicles, capsules and accessory fruits.

10)  Sapindaceae        Koelreuteria paniculata

  • Sapindaceous fruit can be berries, nuts, drupes, schizocarps, capsules or samaras.

August Color Appears at the Washington Park Arboretum
(Part II)

August 25th, 2013 by Pat Chinn-Sloan

Selected cuttings from the Washington Park Arboretum (August 19 – 25, 2013)

1)    Aralia elata (Japanese Angelica Tree)

  • Natural range: Japan, Korea, Russian Far East
  • Can be a tree more than 30 feet tall. Ours are multiple suckers from a spreading root system.
  • Located north of the Wilcox footbridge (40-3W).

2)   Bupleurum fruticosum

  • A dense, multi-stemmed shrub tolerant of exposure and poor soil.
  • Native to Southern Europe and the Mediterranean.
  • Located in our Rock Rose area west of the Sorbus Collection (21-3E).

3)   Kalopanax septemlobus

  • A member of the Aralia family (Araliaceae), it grows to 100 feet. Its lobed leaves might be mistaken for maple until the umbels of flowers appear in July and August.
  • Native to Japan, Korea, and the Russian Far East.
  • Our best is located west of Azalea Way in 15-1W.

4)   Poliothyrsis sinensis

  • Native to the Chinese province of Hupeh
  • Bears clusters of fragrant white flowers
  • Located south of the Woodland Garden near other so-called primitive trees: Trochodendron, Tetracentron, and Euptelia.

5)   Rosa sp. with Spiny Rose Gall

  • These galls are caused by a tiny wasp, probably Dipolepis bicolor, which lays its eggs in the rose’s leaves. The larvae live in the galls until the following spring.
  • This plant is located in 25-1E at the intersection of the Upper and Lower Trails.

August Color Appears at the Washington Park Arboretum

August 2nd, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (7/29/13 - 8/12/13)

Selected cuttings from the Washington Park Arboretum (7/29/13 – 8/12/13)

“Can You Smell That Smell?”

1)   Clerodendrum trichotomum 
(Peanut-Butter Tree)

  • Repugnant, peanut-butter odor when leaves are bruised!
  • Cats are attracted to the smell.
  • See our suckering forest of young trees along the path leading down to the WPA horticultural crew barn.

2)   Prostanthera cuneata      (Alpine Mint-Bush)

  • This low-growing shrub is from Australia and is in the Mint family.
  • When leaves are crushed, they emit a strong fragrance that some liken to eucalyptol and smelly socks.
  • Located in the Australian exhibit of the Pacific Connections Garden.

3)   Ribes malvaceum var. viridifolium   ‘Ortega Beauty’      (Chapparal Current)

  • Native to the coastal mountains of southern California.
  • Malodorous skunky scent when leaves are rubbed like many plants in a chapparal community.
  • Located in the Cascadian entry exhibit of the Pacific Connections Garden.

4)   Umbellularia californica      (Headache Tree)

  • Large broadleaf evergreen tree.
  • Most odoriferous tree in our plant collections by far.
  • Take a deep whiff of the crushed leaves and you’ll know right away why it’s called the headache tree!

5)   Vitex agnus-castus      (Monk’s Pepper)

  • Peppery-smelling leaves some folks compare to Cannabis.
  • An ornamental summer-flowering shrub with many medicinal qualities.
  • Located along Azalea Way at the SE entrance to the Woodland Garden.

July Color Appears at the Washington Park Arboretum (Part II)

July 18th, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (July 15 - 31, 2013)

Selected cuttings from the Washington Park Arboretum   (July 15-31, 2013)

“Quirky Oaks”

1)   Quercus x bushii ‘Seattle Trident’
(Seattle Trident Hybrid Red Oak)

  • Cultivar of a Black Oak and Blackjack Oak hybrid.
  • Developed in Sir Hillier Gardens and Arboretum in England from scion wood collected at Washington Park Arboretum.
  • Located in the Oak Collection, northwest of Azalea Way service road intersection.

2)   Quercus dentata     (Daimyo Oak)

  • Asian native (China, Korea, Japan, Mongolia)
  • Develops an unusually large leaf; occasionally used as a vegetable in native range.
  • Located in the Oak Collection on hillside near Foster Island Road.

3)   Quercus macrocarpa       (Bur Oak)

  • Native to Eastern and Midwestern U.S.
  • Develops a distinct broad canopy as tree matures.
  • Located in the Oak Collection along ridge west of Azalea Way.

4)   Quercus muhlenbergii      (Chinquapin Oak)

  • Broad, native range spanning from New England to northeast Mexico.
  • Large, slow growing tree with chestnut-like foliage.
  • Located in the Oak Collection along ridge west of Azalea Way, north of the Bur Oak.

5)   Quercus pontica      (Armenian Oak)

  • Native to the Caucasus Mountain region of Eastern Europe.
  • Shrubby oak: leaves on new wood remain evergreen, yet older wood becomes deciduous.
  • Located in the Oak Collection near entrance to the Graham Visitor’s Center.

July Color Appears at the Washington Park Arboretum

July 6th, 2013 by Pat Chinn-Sloan

Chile in Seattle

Selected cuttings from the Chilean Gateway Garden in the Washington Park Arboretum (July 1 - 15, 2013)

Selected cuttings from the Chilean Gateway Garden in the Washington Park Arboretum (July 1-15, 2013)

1)  Alstroemeria sp.

  • Commonly called Peruvian Lily or Lily of the Incas.
  • The genus was named after Swedish baron, Claus von Alstroemer (1736-1794) by his close friend, Carolus Linnaeus.
  • Beautiful drifts grace the Chilean Gateway.

2)  Gunnera tinctoria

  • Sometimes referred to as Chilean rhubarb or dinosaur food.
  • The leaves can grow up to 2.5 meters across.
  • Several large clumps dot the Chilean Gateway hillside.

3)  Lobelia tupa

  • Its latex is used as an hallucinogen, which may explain its common name, Tobaco del Diablo.
  • The flowers are red, tubular and two-lipped and are produced in a sympodium pattern.
  • This wonderful perennial is in full bloom in the abundant Chilean Gateway Garden.

4)  Calceolaria integrifolia

  • Its puffy flowers give it its common names Slipperwort, Pocketbook Plant, Pouch Flower or Lady’s Slipper.
  • Can be transient in the garden because it is somewhat tender.
  • One big poofy plant is blooming profusely in the Chilean Gateway.

5)  Luma apiculata

  • Also known as Chilean myrtle. The Mapuche Native Americans call it “Kelumamull” or Orange Wood.
  • It is a slow-growing, evergreen tree with abundant white flowers and beautiful orange-grey bark.
  • We are fortunate to have several nice specimens in the Chilean Gateway planting.

June Color Appears at the Washington Park Arboretum (Part II)

June 21st, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (June 17 - 30, 2013)

Selected cuttings from the Washington Park Arboretum  (June 17 – 30, 2013)

1)  Callistemon sieberi            (Alpine Bottlebrush)

  • This small, spreading shrub is currently showing off its creamy-yellow flowers in bottlebrush-like spikes.
  • Native to Australia, C. sieberi can be found along the footpath of the Australian Entry Garden within the Pacific Connections Garden.

2)  Cytisus battandieri            (Pineapple Broom)

  • Sometimes referred to as Argyrocytisus, this genus of Brooms fall within the family, Fabaceae.
  • Native to Morocco, C. battandieri is an upright tree-like shrub with pineapple-scented flowers.
  • Located on the east side of Arboretum Drive in the Legumes.

3)  Liriodendron tulipfera         (Tulip Tree)

  • A member of the family Magnoliaceae, Liriodendron is a genus of two deciduous trees, L. chinense and L. tulipfera.
  • The solitary, cup-shaped flowers, inconspicuous from a distance, add interest in summer, but are not produced on young plants.
  • Located in the Magnolias, these cuttings came from a tree over 100 feet tall.

4)  Staphylea pinnata             (European Bladdernut)

  • The flowers of this upright shrub have come and gone, but it is the curious bladder-like fruit now on display.
  • Located near Azalea Way amongst the True Ashes.

5)  Tsuga sieboldii                (South Japan Hemlock)

  • Glossy, dark green foliage and smooth, dark gray bark give this tree some distinction within its genus.
  • This Tsuga can be found between the Woodland Garden and the top of Loderi Valley.

June Color Appears at the Washington Park Arboretum

June 10th, 2013 by Pat Chinn-Sloan
Selected cuttings from the Washington Park Arboretum (June 3 - 16, 2013)

Selected cuttings from the Washington Park Arboretum  (June 3 – 16, 2013)

1)  Illicium henryi     (Henry’s Star Anise)

  • This Chinese Illicium is a standout of the genus, as most anise have white or cream-colored flowers.
  • I. henryi can be found along the foot path of the Sino-Himalayan Hillside as well as along the Ridgetop Trail, just west of the Magnolia Collection.

2)  Kalmia latifolia     (Mountain Laurel)

  • This under-used Rhododendron relative is native to the eastern United States.
  • The color of the closed flower buds is often completely different from the open flower color, which ranges from white to deep red, often with a distinctive band inside.
  • There are several cultivars of K. latifolia in the Woodland Garden.

3)  Leptospermum scoparium     (Manuka, New Zealand Tea Tree)

  • The bloom of manuka is profuse and long lasting.
  • Captain Cook supposedly brewed tea for his crew using manuka, which is rich in vitamin C.
  • Specimens can be found in the Australian portion of the Pacific Connections Garden.

4)  Quercus robur  ‘Concordia’     (Golden English Oak)

  • The golden color of the young growth fades to green as the leaf ages.
  • Our specimen can be seen on Azalea Way just south of the Graham Visitors Center.

5)  Rhododendron  ‘Teddy Bear’

  • This cultivar of Rhododendron is a cross between R. bureavii and R. degronianum ssp. yakushimanum.
  • The thin white indumentum on the upper side of the leaf goes away in time, while the thick indumentum of the underside remains and turns brown.
  • This Rhododendron can be found in the Puget Sound Rhododendron Hybridizers Garden along Azalea Way.

May Color Appears at the Washington Park Arboretum
(Part II)

May 23rd, 2013 by Pat Chinn-Sloan

Selected cuttings from the Washington Park Arboretum (May 13 - 26, 2013)

Selected cuttings from the Washington Park Arboretum (May 13 – 26, 2013)

1)   Aesculus x carnea    ‘Fort McNair’

  • A hybrid between A. pavia and A. hippocastanum, it probably originated as a chance hybrid made by insects in 19th-century Germany.
  • Selected at the fort of the same name in Washington, D.C., flowers are pink with a yellow throat.
  • It can be found on Azalea Way, across from the Woodland Garden.


Close-up view of the unusual orange flowers of the Buddleja globosa

Close-up view of the unusual orange flowers of the Buddleja globosa

2)   Buddleja globosa

  • A species of flowering plant endemic to Chile and Argentina, where it grows in dry and moist forest.
  • It can be found at both ends of the Arboretum at the Holmdahl Rockery and in the Graham Visitor Center parking lot.


3)   Embothrium coccineum   (Chilean Fire tree)

  • A small evergreen tree from the temperate forests of Chile and Argentina.
  • The plant was introduced to Europe by William Lobb during his plant collecting expedition to the Valdivian temperate rain forests in 1845–1848. It was described by Kew Gardens thusly: “Perhaps no tree cultivated in the open air in the British Isles gives so striking and brilliant a display as this does.”
  • There are several small specimens in the Chilean Gateway, and one large one just north of the bus turnaround on Arboretum Drive.

4)  Rhododendron x  ‘Favor Major’

  • Hybridized by L. De Rothschild, the founder of Exbury Gardens in the United Kingdom.
  • A beautiful orange Azalea, located on Arboretum Drive at the Rhododendron Glen parking lots.

5)  Syringa josikaea   (Hungarian Lilac)

  • A species of lilac native to central and eastern Europe, in the Carpathian Mountains in Hungary, Romania, and western Ukraine.
  • Located in the Syringa Collection on Azalea Way, just south of the Woodland Garden.

May Color Appears at the Washington Park Arboretum

May 5th, 2013 by Pat Chinn-Sloan

Selected cuttings from the Washington Park Arboretum (April 29, 2013 - May 12, 2013)

1)   Acer circinatum (Vine maple)

  • Taken for granted around here, this time of year our vine maple is most eye-catching in flower.
  • Located throughout our native matrix as a deciduous forest understory tree.
  • Vine maple is native to the North American west coast from British Columbia to California.

2)   Acer cissifolium   (Vine-leaf maple)

  • Despite their similar common names, vine maple and vine-leaf maple could hardly be more different. The Acer cissifolium leaf is compound, composed of three leaflets; Acer circinatum has almost round leaves. The flowers of Acer cissifolium have four petals (unusual for a maple) and are arranged in racemes while those of Acer circinatum are five-petaled and in panicles.
  • Acer cissifolium is native to Japan. In the Arboretum, it is located in Rhododendron Glen (12-3E) and in the Asiatic Maples (27-B).

3)   Broussonetia kazinoki

  • The inner bark is prized in Japan for making high-quality paper.
  • A related species Broussonetia paperifera (paper mulberry) is used for paper from Myanmar to Japan and in Polynesia for the paper-like “tapa cloth”.
  • The fruit begin to develop before the flowers produce pollen.
  • Our Broussonetia is north of the Winter Garden in 35-3E and 36-2E.

4)   Rhododendron augustinii

  • Provides the mauve backdrop for the beds along Azalea Way and in Rhododendron Glen.
  • One of many plants discovered by and named for Augustine Henry in western China.

5)   Viburnum macrocephalum

  • A China native introduced by Robert Fortune in 1844.
  • Located in the Pacific Connections China Entry Garden.