1. BIOLOGY 2404a FLORA AND VEGETATION OF ONTARIO http://instruct.uwo.ca/biology/2404a Fall 2009 Lecture 2 Dr. R. Greg Thorn Department of Biology, UWO

2. Plant and Flower Parts We will see more of this in Lab, but this introduction will be useful preparation for our next Field Trips Lichens Bryophytes Ferns Gymnosperms Flowering Plants

3. Stramenopila A slight revision based on evidence from sequences of more genes, showing the linkage of the SAR (Stramenopila, Alveolates & Rhizaria), and of these with the Plants (“Primoplantae” in this figure); the Unikonts and Excavates remain as distinct lineages. Plants

7. N.V. V. S. G. A. Sp.

11. N.V. V. S. G. A. Sp.

14. N.V. V. S. G. A. Sp.

18. Naked sori (clusters of sporangia) in Dennstaedtia

19. Sori arranged along leaf margins, protected by “false indusium” Bracken fern, Pteridium aquilinum

20. Botrychium and Ophioglossum, eusporangiate Ophioglossales

21. Sori in sensitive fern (Onoclea sensibilis) are on separate fertile fronds, enclosed in spherical capsules formed by lobes of the leaflets

22. N.V. V. S. G. A. Sp.

23. Female Cycas siamensis with seeds on upper surfaces of sporophylls

25. Ephedra, male plants and “microsporangiate strobili”

26. Bristle-cone pine, Pinus longaeva, needles in fascicles of five, and young (left) and mature (right) ovulate cones

27. Pinus radiata microsporangiate cones shedding pollen

28. N.V. V. S. G. A. Sp.

29. Hepatica americana (Ranunculaceae, a basal eudicot)

30. Parts of a lily flower

38. Lemna gibba: flowering plant with two stamens and one style

39. An orchid flower (Cattleya)

40. An orchid flower (l) compared to a radially symmetrical flower (r)

41. Types of inflorescences (arrangements of flowers). I

42. Types of inflorescences (arrangements of flowers). II

43. Types of inflorescences (arrangements of flowers). III

44. Types of inflorescences (arrangements of flowers). IV

45. Switchgrass (Panicum virgatum)

46. Quackgrass (Elymus repens)

47. Lupine (Lupinus)

48. Mertensia

49. Water hemlock (Cicuta maculata)

50. A catkin, of birch (Betulaceae)

51. Staminate catkins and acorns of tanbark oak (Lithocarpus)

52. Flowers of many grasses, including corn (Zea mays), are wind- pollinated. Staminate flowers (left) and ovulate flowers (right)

53. Stigma Stamens Inflorescences of Elymus (= Agropyron) a grass related to wheat

54. A grass spikelet, a cluster of florets. Spikelets may be arranged in a variety of inflorescence types (see slides #41-42)

55. An individual grass floret dissected out of a spikelet

56. The grass floret dissected still further, to show the androecium and gynoecium

57. A typical inflorescence of a composite (Asteraceae) Ray flowers Disk flowers

58. Composite inflorescence and flowers dissected and explained

59. Thistles have only disk flowers

60. Positioning of the ovary within a flower, from ancestral (left) to derived (right)

61. Placentation, the arrangement of ovules within the ovary

62. Floral Formulae KCAG system (Smith 1977) *, 5, 5, , 10, capsule (Judd et al 2002) * = radial symmetry X = bilateral symmetry $ = asymmetry (Judd et al 2002)