The proposed plan calls for planting new acquisitions in most botanical families and genera wherever they will grow best, or integrating them into other types of displays. Retaining, enhancing or creating new taxonomic exhibits can also be expected--keeping in mind that the principal collections display goal will be to simulate a particular forest formation type.

The following list of taxonomic clusters includes both exhibits warranting fully developed interpretation (e.g., Acer/maple) and those which might require simply a sign. Although some of these exhibits are presently labeled as collections on the Collections Plan, they do not comprise the entire collection for each taxonomic group. Instead, they are a selection of taxa that will grow well together and that support chosen interpretive messages (e.g., morphological variation, taxonomic breadth or geographic range).

The Arboretum Plan will de-emphasize over time any existing taxonomic clusters not listed here or in other plan developments. It may be appropriate to add unrelated plants to either old and new taxonomic clusters within the forest formations to visually integrate these displays into their respective formation type (e.g., supplementing the magnolia display with more conifers to better represent a mixed coniferous-broadleaf forest).

Acer/maple
A bold new maple exhibit will cover the southwestern slope of the Woodland Amphitheater, stretching into the Wooldland Glen to the west. This area should be sufficient in size to accommodate companion plants and groups of the same taxon as needed to create landscape effects.

Alnus/alder, Populus/poplar, Fraxinus/ash
Groupings of Pacific Northwest native species in these genera will form the northern part of the valley bottom along the west side of Lake Washington Boulevard. Further south will be species from outside the region. These groupings may simply be labeled, with their stories told in the Arboretum's literature and during guided tours.

Betula/birch
This will be exhibited along the west side of Water Meadow (the flats).

Ericaceae/heath
To illustrate the diversity found in this large family the plan calls for a collection of cool-temperate ericaceous trees and shrubs in Rhododendron Glen. Besides Rhododendron, representative genera could include Vaccinium/huckleberry, Zenobia, Ledum, Menziesia, Kalmia/mountain laurel, Oxydendrum/sourwood, Enkianthus, and Gaultheria/salal. If the Phytophthera in the northeast part of the glen can be controlled, Arctostaphylos/bearberry and Arbutus/madrone might be good choices due to the prime southwest exposure.

Ilex/holly
A small, but intensively designed holly exhibit will be assembled from newly acquired, repropagated and/or relocated specimens at a spot near the new maintenance complex. Other important taxa in the existing holly collection (site of the renovated Madrona Terrace) will be repropagated and relocated to the Asian Hillside or elsewhere in the Arboretum.

Leguminosae/legume
A smaller, redeveloped exhibit interpreting the diversity and economic value of this worldwide family is proposed at the site of the existing legume display. It will incorporate some existing specimens and some added specimens with showy flowers (e.g., Albizzia julibrissin/silk tree).

Magnolia/magnolia
A species magnolia exhibit showing morphological variation and geographic range will be created from the existing display near Ridgetop Retreat. The rest of the Arboretum's collection of magnolia species and cultivars will adorn Azalea Way and other locations.

Quercus/Oak
A small oak exhibit, also depicting diversity and geographic range, is proposed for the area southeast of the Wilcox Bridge. Space may be available for only 10-30 specimens. The Arboretum's existing oak collection to the north is generally crowded and in poor condition. Many of the taxa there will be re-acquired and planted elsewhere in the Arboretum to make room for the new learning center.

Salix/willow
Native shrubby willows, selected to frame desirable views, will occupy varying length segments of the Willow Bay shoreline. A discrete area for non-native willows has not yet been identified. These trees can be worked into the deciduous forest formation in the valley bottom, particularly along the Riparian Forest Trail.

Sorbus/mountain ash
The Mulligan Sorbus collection will remain on its present site. There will be room for the addition of a few more specimens at both the north and south ends of the display, although it will be important to maintain a sense of open space in these two areas.
Other Taxa
Other taxa will be displayed in synoptic collections which will represent taxonomic and morphological diversity of these groups, including: Cornus/dogwood, Pinus/pine, Picea/spruce, Prunus/cherry, plum, etc., Berberis/barberry, Hamamelidaceae/witch-hazel family, Caprifoliaceae/honeysuckle family, Camellia and Stewartia, and Wisteria.