Lecture 2 Flashcards
What are four major groups of gymnosperms
Gnetophytes, pinales, ginkgoales, cycadales
Name some characteristics of ginkgoaceae family
Only extant species is Gingko biloba
Fan shaped, dichotomously veined leaf
Deciduous
Dioecious
Can live over 1000 years
What are some characteristics of cycadales?
Palmlike
Reproductive structures are in strobili
Specialized root system that houses cyanobacteria –> can fix nitrogen
What is the most diverse group of gymnosperms?
Pinales
Name some families that are part of the gymnosperm group
Araucariaceae (monkey puzzle)
Podocarpaceae: only in Southern Hemisphere
Pinaceae (spruce, fur, pine)
Cuppressaceae (juniper, cedar)
Taxaceae (yew)
What are some common traits of Pinaceae?
Trees and shrubs
Resin canals
Found in Northern Hemisphere
Cones with spirally arranged, flattened bract complexes
Seeds with a long, terminal wing
Are species in the Pinaceae family monoecious or diecious?
Monoecious
What species in the family of Pinaceae have singly attached leaves (that we have seen in the field)?
Picea glauca (white spruce) : needles more triangular than flat, longer needles compared to Picea mariana, blue-ish green needles
Picea mariana (black spruce) : needles dull gray-ish green, straight with white dots
Abies balsamea (balsam fir): leaves a circular scar on twig when needle is detached, flat needles, longer than hemlock
Tsuga canadensis (hemlock): flat 2D needles, 1cm long, shorter needles compared to Abies balsamea, shiny on top, white under leaf
What are some common traits in the Cupressaceae family?
Trees of shrubs
Resin canals
Seeds with pits and ridges
0 or 2-3 short wings
What family is Thuja occidentalis (eastern white cedar) a part of? What are some traits?
Cupressaceae
Folded half small leaves, scale-like foliage
What is the group Sequoioideae?
A subfamily in Cupressaceae of giant trees
Only few species (others extinct)
Very large and long lived, habitats have mild climates (temperature and precipitation)
Within this group we find coast and giant redwoods
What are some common traits in the Taxaceae family?
Taxine (toxic chemical) in all parts except the fleshy aril surrounding the seed
Deer can eat yew, but now cows, sheep, humans, etc.
Important chemotherapy drug
What are the two main groups of seed plants?
Gymnosperms: cycads, gingko, conifers, gnetophytes
Angiosperms: ANA grade, magnoliids, eudicots, monocots
How did carpels evolve?
Evolved from a modified leaf
- modifications of leaf tissues gave rise to the structures in a flower
Ovules (sporangia) became enclosed within a carpel (ovary) that then matured into a fruit
Petals and sepals are modified bracts surrounding the stamens and carpels
What is an example of a way that we have learnt about the history of flowering plants?
Flowers do not fossilize very well. However, fossil pollen has given the first physical evidence of angiosperm emergence.
Pollen has many morphological features and preserves well in the fossil record: very informative for studying ancient plant communities and evolution
What did the earliest flowers look like?
Phylogenetic and fossil evidence suggests that the earliest flowers were small, perfect (male and female in the same flower)
Had radial symmetry
No fusion of parts
Multiple layers of tepals and stamens. Multiple separate carpels, several pistils and separate stamens
What are the 3 orders included in the ANA grade group?
Amborellales, Nymphaeales, Austrobailyales
List some common traits of Amborellales
Only one extant species in the order
Dioecious
Tepals
Numerous stamens
Vessel-less wood
Endemic to New Caledonia
Name some common traits in the Nymphaeaceae family?
Water lily family
All aquatic plants
Large floating leaves with stems attached at the base of the leaf (peltate)
- leaves arising from rhizomes
Style not well differentiated
Flowers with few to many spirally arranged perianth parts and many stamens (petals grading into stamens)
Many fused carpels
What is the Nymphaeaceae flower structure?
Superior, inferior or partly inferior ovary
Laminar placentation
Stamens change from petaloid to normal
Are Lotus a part of the Nymphaeaceae family?
No, they are a part of the Proteales order (monocot group)
Name a few traits of the Austrobailyales group
Star anise
All are woody plants that are not from North America (found in the tropical Americas, Southeast Asia, Australia, and South Pacific)
What are the 3 orders in the Magnoliid clade?
Magnoliales
Laureales
Piperales
What are three families in the Magnoliales order?
Magnoliaceae
Myristicaceae
Annonaceae
What is a family in the Laureales order?
Lauraceae
What are 2 families in the Piperales order?
Piperaceae
Aristolochiaceae
What are characteristics found in the Magnoliaceae family (type of leaf, uni or bisexual flowers, sepals/petals)?
- Trees with alternate, simple leaves
- Large bisexual flowers with numerous spirally arranged flower parts
- Sepals and petals separate (not fused), often similar in colour and texture (tepals) with gradual gradation from sepals to petals
How many stamens, carpels, ovules in Magnoliaceae family?
Many stamens and many separate carpels
Each carpel with two ovules; one often aborts
What type of fruit is produced in Magnoliaceae family?
Samara or compound follicle
What difference do monocot stems have in comparison to ANA grade or eudicot stems
Monocot has scattered vascular bundles and no cambium (circular layer of cells in a plant that provides unspecialized cells to promote growth)
All monocots have therefore lost the genes related to the growth of vascular cambium (i.e. wood production ability)
Eudicots that are non-woody retain these genes but have them turned off
What group is the Araceae (Calla lily) family a part of? What are some common house plants in this family?
Monocots
Peace lily, monstera
What are some traits of Arisaema triphyllum (jack-in-the-pulpit)?
Produces male flowers when young/small and female flowers when older
Sex is determined by amount of stored carbohydrates in the corm
Can change back to male in next season if leaf is damaged or growing conditions are poor
Moist, shaded (wooded) habitat
What family is Lemna minor (duckweed) a part of?
Araceae
Small aquatic plant
What is a spathe and a spadix?
a spike of minute flowers closely arranged around a fleshy axis and typically enclosed in a spathe (large bract)
(Think of a peace lily flower)
Characteristics in the Araceae family
What are the characteristics of the Araceae family?
- Herbs from rhizomes, corms, or tubers, or small floating plants with very reduced parts
- Inflorescence a spadix surrounded by a spathe; or a single pistil and stamen
- Flower perfect or unisexual; perfect flowers have small perianth of 4-6 sepals
- Stamens 4, 6 or 8; superior ovary of 2-3 fused carpels
- Flowers very reduced on floating aquatic taxa
What is the fruit in Araceae family?
Fruit a berry or utricle (like an achene but with the exocarp puffed around the seed)
Where are Araceae species found?
Mainly in wetlands; some food and medicinal plants
Global distribution (except Antarctica)
What are two common genera of emergent aquatic plants in the Alismataceae family (water-plantain family)?
Alisma
Sagittaria
What are characteristics of Alisma?
3 sepals, 3 petals, 6 stamens
numerous separate carpels
flowers perfect
What are characteristics of Sagittaria?
Arrow-shaped leaves
Unisexual flowers similar to those of Alisma, but with numerous stamens in male flowers
Plants are monoecious (male and female flowers on same plant)
What are some characteristics of Potamogeton (genus in the Potamogetonaceae family)?
- Aquatic (freshwater) plants with floating or submerged leaves or both
- Leaves with prominent stipules, two morphologies
- 4-merous flowers (4 sepals, 4 stamens, 4 carpels): separate stamens, separate carpels
What kind of fruit in genus of Potamogeton?
Racemes of fruits (4 achenes or drupelets per flower) rise above the water surface or float on the surface
What are some characteristics of Liliaceae?
Simple, entire leaves; alternate and spirally attached to stem, or in whorls
Tepals often with spots or lines
Bulbs or rhizomes with contractile roots (used to pull the plant deeper into the ground)
Where are Liliaceae plants found?
Mostly understory plants of moderate moisture (mesic) forests in the Northern hemisphere
What type of fruit is found in Liliaceae family?
Fruits usually a capsule, more uncommonly berries
What species of Liliales did we see in the field?
Trillium grandiflorum (a part of the Melanthiaceae family)
- ovary superior or inferior
- Unique type of seed coat
- Inflorescence often an umbel
What species of Asparagaceae did we see in the field?
Maianthemum canadense
Very common boreal species, also in peatlands and northern hardwood zones forest understories
What is one of the largest families of plants?
Orchidaceae
Describe the unusual flower morphology in the Orchidaceae family
Androecium and gynoecium united into a column that is found opposite the lip (lip serves to attract insects, acts as a landing platform for them)
Some groups have two anthers, some have one. Each forms a pollinia
What does resupinate mean?
The flower is “upside-down” because the pedicel and/or peduncle is twisted (lip on bottom, column on top)
Some species in the Orchidaceae family are resupinate, some are not
List traits from the Orchidaceae family
- Herbs or vines from rhizomes, corms, or root-tubers
- Terrestrial or epiphytic
- Flowers 3-parted with bilateral symmetry; one petal (lip) highly modified
- Androecium and gynoecium united into a column that is found opposite the lip
- Stamens reduced to 2 or 1
- Pollen in pollinia (pollen sacs) in most genera
What is the habitat of species in the Orchidaceae family?
Terrestrial, most diverse in peatlands and rich forests
What is the Iris flower structure (Iridaceae family)?
3-merous flowers
Linear equitant leaves
Inferior ovary
3 petaloid sepals
3 petals (sometimes very reduced)
3 style branches
3 stamens
What type of fruits do Iris produce? With what type of placentation?
Capsules fruits with axile placentation
