Today’s plants (all within subclass Rosidae)

1. Today’s plants (all within subclass Rosidae) Rosid trees Salicacaeae Salix (willows) Populus (aspens, cottonwoods) Betulaceae Betula(birches) Alnus(alders) “Aceraceae” (now in Sapindaceae) Acer(maples)

2.  Salicaceae - Willow family Habitats diverse, but generally high elevation or riparian Growth habit trees, shrubs Leaves alternate simple dentate with stipules

3.  Salicaceae - Willow family Flowers unisexual (imperfect) species usually dioecious may be wind-pollinated or insect pollinated Inflorescences catkins M M F F M F F M M F M F M F M F M F

4. catkin = a dense inflorescence of unisexual, apetalous flowers

5.  Salicaceae - Willow family Sepals 0 or many often reduced may be connate Petals 0 Stamens 2 - many (in staminate flowers only!) Salix - male flowers

7.  Salicaceae - Willow family Gynoecium (in pistillate flowers only!) syncarpous, 2 - 4 carpels superior ovary stigma often lobed bract

9.  Salicaceae - Willow family Fruit type: capsule Seeds: comose (w/long hairs) Cottonwood seeds Seeds dispersed by wind and water

10.  Salix - Willows In Montana: 50 species; diverse habitats Growth habit: few trees, many shrubs or creeping shrubs S. arctica S. fragilis

11.  Salix - Willows many species of riparian shrubs Often spreading vegetatively Often hybridizing

12.  Populus - Aspens, Cottonwoods In Montana: 5 species; riparian or montane/subalpine Growth habit: trees P. tremuloides (Aspen) P. balsamifera (Cottonwood)

15. Elk & Aspen

16.  Salicaceae - Willow family Salix vs. Populus mostly shrubs vs. mostly trees 1 bud scale vs. many bud scales long leaves w/ vs. broad leaves w/ short petioles long petioles catkins erect vs. catkins pendulous 1-8 stamens vs. 6-many stamens

17. Salicaceae - Willow family Salix: 1 bud scale Populus: > 1 bud scale

18. Salicaceae - Willow family Salix Populus

19. Salicaceae - Willow family Salix (upright) Populus (hanging)

20.  Betulaceae - Birch family Distribution: world-wide; primarily north temperate In Montana: 3 genera, 6 species Growth Habit: trees/shrubs Leaves: alternate, simple serrate or doubly serrate Genera to know: Betula (birch) Alnus(alder)

21.  Betulaceae - Birch family • Inflorescences: catkins of reduced flowers • Flowers: unisexual • plants monoecious • wind-pollinated female catkin male catkin

22.  Betulaceae - Birch family Sepals 1 - 6 often scale-like always distinct Petals 0 Stamens 2 - 8 male flowers

23.  Betulaceae - Birch family Gynoecium 2 fused carpels in dense, cone-like catkin with bracts Fruit types nutlet samara (winged nutlet)

24.  Betula - Birches In Montana: 3 species; often near streams/lake shores Growth habit: trees/shrubs B. occidentalis (Water Birch) B. papyrifera (Paper Birch)

25.  Alnus - Alders In Montana: 1-2 species; wet areas, near streams/shores Growth habit: small trees/shrubs here (large trees in PNW)

26.  Betulaceae - Birch family Alnus: female catkins woody and persistent Betula: female catkins not woody

27.  Betulaceae - Birch family Alnus: stalked buds Betula: blistered bark

28. “Aceraceae” - Maple family Now in Sapindaceae (large family of mostly tropical trees) In Montana: 1 genus w/ 3 native species & 1 invasive Habitat: primarily in riparian areas, open pine forest

29.  Acer - Maples Growth habit: trees/shrubs Leaves: opposite simple, often palmately lobed 1 sp. pinnately compound A. glabrum (Rocky Mtn. Maple) A. negundo (Box Elder)

30.  Acer - Maples Inflorescences: umbels w/ long flower stalks Flowers unisexual & regular trees monoecious Sepals 4 or 5 Petals 0 Stamens usually 8 (in staminate flowers)

31.  Acer - Maples Gynoecium (pistillate flowers only) 2 fused carpels => 1 ovary w/ 2 styles ovary superior female flowers have non-functional stamens

32.  Acer - Maples Fruit type samara = winged nutlet (in pairs => schizoid samara)

33. Norway Maple A. platanoides

34. Ulmaceae - Elms, Hackberry

35. Fagaceae - Oaks, Beeches, Chestnuts

36. Fagaceae - Oaks, Beeches, Chestnuts