Week 14

1. Week 14 Plant Group #6 Evergreens Pine, Spruce, Fir, and Hemlock

2. Two-Needled Pines • Jack Pine • Japanese Red Pine • Mugo Pine • Austrian Pine • Red Pine • Scots Pine

3. Pinus banksiana – Jack Pine Location: Southeast of campus cemetery Short needles (<2”) that are divergent/wide spreading Dull green appearance and abundant cones in pairs of two Cones take two seasons to develop and open to release seeds Very tolerant of bad soils and harsh conditions Irregular form, so best when planted in masses

4. Pinus densiflora – Japanese Red Pine Location: Lagomarcino Courtyard Soft and flexible 3-4” needles with serrations Bright green needles that are usually in bunches at the tip of the stem Buds long, pointed, and reddish Prominent sheath up to 1/2” Slow growing, often multistemed, and reaching 50’ tall. Orange/red flaky bark

5. Pinus mugo – Mugo Pine Location: North of Landscape Architecture Variable in its form…some cultivars are small compact shrubs while others are multi-stemmed trees Bright green curved needles 1-2.5” long and serrate Gray platy bark and medium sized cones Popular landscape shrub ID may be difficult

6. Pinus nigra – Austrian Pine Location: On the walk from Horticulture to Morrill Hall Long (4-7”), thick, stiff, and sharp needles Large resinous white buds are present in the fall Male flowers are often still present in fall Persistent sheet (1/3”) may be present Silver color plated bark. No longer recommend for planting because of disease problems (Diplodia and Dothistroma blight), which are prevalent on campus Salt tolerant evergreen Open form when mature

7. Pinus resinosa – Red Pine Location: South side of Pearson Hall Long (5”) needles that have serrations and are easily broken Sharp pointed medium green needles with a white sheath Needles are thinner and shorter than those of P. nigra Prominent red-orange blotches of bark A poor choice in the Midwest Commonly used for forestry

8. Pinus sylvestris – Scots Pine Location: West of the Hub Green/blue needles are sharp, twisted, serrate, and up to 4” long Conical shape when young but open and flat-topped with age Attractive red flaky bark especially higher up in the canopy Very tolerant tree that has been widely used, but Diplodia needle cast limits its use Popular Christmas tree Can reach 30-50’ tall in the landscape

9. Three-Needled Pines • Lacebark Pine • Ponderosa Pine

10. Pinus bungeana – Lacebark Pine Location: Southeast of Pearson Hall Groups of three needles which are rubbery, medium-green and have little serration Very popular pine because of attractive multi-color bark and tolerance to bad soils Newest wood on branches has greenish color Its has an open canopy that exposes the nice bark Fast-growing, reaches 30-40’ tall Excellent choice, could see more widespread use

11. Pinus ponderosa – Ponderosa Pine Location: Northwest corner of the Armory Bundles of three needles that are very long (up to 10”) Note that not all fascicles have three needles! Needles are light green and have minute serrations Narrow and upright when young and becoming irregular with age Fast-growing, reaches up to 80’ tall Cones are umbo (points on scales) Limited landscape use because of its very large size and coarseness

12. Five-Needled Pines • Swiss Stone Pine • Limber Pine • Korean Pine • Eastern White Pine

13. Pinus cembra –Swiss Stone Pine Location: North side of Music Hall 3-4” needles that are bluish/green to light green Needles are stiff, straight, serrate, but soft to the touch Orange/brown pubescence on new stems Leaves have a 5 year life span leading to a dense canopy. The stems are heavily covered in needles Makes a very good evergreen screen Slowly reaches 35’ tall and 10-15’ wide High cost is a drawback

14. Pinus flexilis – Limber Pine Location: SW of Horticulture near the chain fence 2.5-3.5” needles that are bluish/green and slightly twisted The needles lack serrations (Very important to distinguish it from other 5 needle pines!) Its stems are stout and very flexible Pyramidal when young and flat-topped with age Will reach 30-50’ tall ‘Glauca’ &‘Vanderwolf’s Pyramid’ are popular blue cultivars A good pine for landscaping old young

15. Pinus koraiensis – Korean Pine Location: West of the Hub 2.25-4.5” long needles Needles are dark green and have white stomatal lines Course toothed margins and blunt tips Terminal buds have loose scales Young shoots are reddish brown and may have pubescence Slow-growing tree that is pyramidal when young A very adaptable tree that should be utilized more!

16. Pinus strobus – Eastern White Pine Location: South of Horticulture. Thin wispy needles are ~4” long. Serrate margins and two stomatal lines on underside (giving a blue cast) Fine textured pine that is pyramidal, fast growing, and reaches 50-80’ tall Yellow fall color as oldest needles die and fall off Cones are fairly large Susceptible to salt, air pollution, and white pine blister rust, but is probably the most commonly planted pine on campus and elsewhere in the Midwest Can be a good choice when placed in the right spot Native to northeast Iowa

17. Spruce • Spruces have needles that are attached singly • Needles are square

18. Picea abies – Norway Spruce Location: East of Beardshear Hall Stiff pointed needles 0.5 to 1” long Needles have 2-3 stomatal lines; white spruce has 2-5 Horizontal branches have pendulous branchlets Its cones are the largest of the spruces we will study (4-6” long) Form is variable; pyramidal and uniform when young, but can become irregular and ratty with age It has a fast growth rate, reaching 40-60’ tall and 30’ wide Very widely planted, but there are better choices Many dwarf cultivars of the species; Birds Nest Spruce is one of them

19. Picea glauca – White Spruce Location: North of the Hub Needles are very small (1/2”), point forward on branch Stiff branching and sharp pointed needles 2-5 stomatal lineson needles Glaucous, medium green in color Small cones when compared to P. abies Tree may get 60’ tall and 20’ wide It has a compact pyramidal habit when young, but gets loose with age The species and Picea glauca var. densata (Black Hills Spruce) are good alternatives to Colorado blue spruce

20. Picea pungens var. glauca – Colorado Blue Spruce Location: Northwest of Horticulture Lots of variation in the “blueness” of the needles Needles spread around the stem and are 0.75-1.25” long They are very sharp and rigid Scales on terminal buds are often reflexed (curved back) The form is conical and very dense with a medium growth rate Cones can be up to 5” long and 1” wide Insect and disease problems (spider mites, galls, needlecasts and cankers) lead to a short life (30 years) for this species in the Midwest Although common and widely planted, other species are better adapted to our climate

21. Picea omorika – Serbian Spruce Location: SW corner of Science Hall Pendulous branches similar to Norway Spruce Needles point toward the branch tips Needles are 0.5-1” long and dark green with two stomatal lines on the underside Has done well on campus but growth has been slow Dirr refers to it as the most ornamentally attractive spruce Reaches 60’ tall and 25’ wide with a conical form

22. Fir • Needles are attached singly • Needles are flat (not square)

23. Abies concolor – White Fir Location: South side of Lagomarcino Similar appearance to Colorado blue spruce, but needles are flat and point upward 2-3” blunt needles are thick, rubbery, and glaucous, giving a blue appearance 4-5” cones on the top 1/3 of mature trees; disintegrate quickly Golden brown buds often in groups of three Circular leaf scar and smooth stem Blue spruce leaves a rough stem at location of the leaf scar Most adaptable fir to our climate (dry summers)

24. Pseudotsuga menziesii – Douglas-Fir Location: SW of Beardshear Needles have a bluish cast and are flatand blunt Needles are 1-1.5” long and arranged spirally around the stem Terminal buds are pointed and shiny chestnut-brown Cones have unique forked bracts Tree may reach 80’ tall and 20’ wide, with a pyramidal form

25. Tsuga canadensis – Canadian Hemlock Location: SW corner of Curtiss Hall Small (1/2”), flat needles are arranged singly and spirally around the stem Stomatal lines on underside of leaf Produces numerous very small cones Has pubescent shoots Does well in shade but requires well-drained soils 40-70’ tall with a 25-30’ spread Graceful, fine-textured evergreen with pyramidal shape