1)    Alnus glutinosa ssp. betuloides Birch-leaved Alder Native to the mountains of eastern Turkey. Listed as a threatened species by the International Union for Conservation of Nature. Autumn brings pendulous male catkins and the mature female cones.   2)   Catalpa x erubescens        Indian Bean Tree Uncommon tree with fetching, large, chocolate-purple young leaves that turn green. Late summer brings masses of creamy white flowers flecked with yellow. 

The State of the Arboretum 1)   Liriodendron tulipifera        Tulip Tree The state tree of Indiana. The Western Hemisphere representative of the two-species genus Liriodendron, and the tallest eastern hardwood. 2)   Pinus resinosa                 Red Pine The state tree of Minnesota. It is a long-lived tree, reaching a maximum age of about 500 years. The wood is commercially valuable in forestry for timber and paper pulp, and the tree is also used for landscaping. 

1)   Poliothyrsis sinensis A rare and very attractive small flowering tree of upright, open habit. Originally brought from China to the Arnold Arboretum by E.H. Wilson. Big 6-8” mildly fragrant, creamy flower clusters (corymbose panicles) make a significant contribution to the August-September garden. Located in grid 30-3E, near the south entrance to the Woodland Garden along Arboretum Drive. 2)   Daphniphyllum macropodum This dioecious plant (translation = “of two houses”) needs plants of both sexes to seed. 

1)   Houpu Magnolia    (Magnolia officinalis var. biloba) Unique bi-lobed leaf 8-12″ in length 4-8″ seed pods on display in late summer Located in grid 27-1W in the Rhododendron hybrid bed 2)   Sargent Magnolia    (Magnolia sargentiana var. robusta) Bears large pink flowers in spring Large, pinkish-red fruit appear in late summer and fall Located in grid 13-7E in Rhododendron Glen 3)   Rehder Tree    (Rehderodendron macrocarpum) White flowers appear in spring 3-4″ seed pods weigh down branches in late summer Located in grid 13-6E and elsewhere throughout the Washington Park Arboretum 4)   Himalayan Stachyurus    (Stachyurus himilaicus) Deciduous or semi-evergreen shrub to height of 10’ Displays clusters of flowers in early spring Located in grid 25-1W 5)   Yunnan Stachyurus    (Stachyurus yunnanensis) Small evergreen shrub to height of 6’ Chains of white flowers appear in spring Located in grid 25-1W 

“Sporting Wood” 1)    White Ash    (Fraxinus americana) Tough, plentiful, and easily bent into curves, Ash is used in tennis racquets, billiard cues, skis, and baseball bats. White Ash is native to eastern and central North America. This cutting is from the cultivar ‘Rose Hill’, located in grid 47-3E near the Lagoons. 2)   Common Box    (Buxus sempervirens) Used for crocquet balls because of its hardness. 

                    1)   Erhetia dicksonii Ornamental tree from Asia with corky bark and fragrant white terminal cymes. Located along path heading up to Rhododendron Glen from Azalea Way, grid 15-1E. Go to link below for thorough description and uses. http://www.arthurleej.com/p-o-m-July07.html 2)   Holodiscus discolor      (Ocean Spray) My favorite summer flowering Pacific Northwest native deciduous shrub. 

1)  Hydrangea macrophylla   ‘Madame Emile Mouillere’ A blizzard white beauty all summer, long considered the best white mop head. A charming companion to evergreen shrubs. A beautiful 70-year old specimen graces the Hydrangea Collection along the Arboretum Drive. 2)  Leucothoe davisiae      (Sierra Laurel) Native to the mountains of northern California and southern Oregon. One of 4,000 species in the Ericaceae family. 

1)    Crataegus crus-galli        Cockspur Hawthorn Native to eastern North America, this small deciduous tree has a pleasant habit and is now showing off its small white flowers, but don’t get too close!  The rigid thorns can be up to three inches long. Hawthorns are classified within the plant family Rosaceae, and are allied to Cotoneaster, Mespilus, and Pyracantha. This specimen is located on the east side of Lake Washington Boulevard, just north of the Boyer Parking Lot. 

“That’s Ancient History” 1)   Cedrus libani      (Cedar of Lebanon) The Cedar of Lebanon has been prized for its high quality timber, oils and resins for thousands of years. It was used by the Phoenicians and Egyptians and was mentioned in the Epic of Gilgamesh. Because of its significance, the word “cedar” is mentioned 75 times in the Bible, and played a pivotal role in the cementing of the Phoenician-Hebrew relationship. 

1)   Rhododendron spp.           Azalea Azaleas are in the genus Rhododendron, with evergreen azaleas in the subgenus Tsutsusi and deciduous azaleas in the subgenus Pentanthera. The Olmstead Brothers originally planned for 11,000 azaleas to be planted along Azalea Way. More than 3,100 have been planted and over 2,000 remain. Azalea Way contains 21 species of azalea and more than 200 hybrids. 2)  Tsuga heterophylla           Western Hemlock Our native western hemlocks are currently laden with new female cones which are deep purple when immature.