Lecture 9 Core Astrids: Lamiids and Tundra Ecosystem Flashcards
What are leaf/stem characteristics of the Plantaginaceae family?
- herbaceous
- leaves simple
- no stipules
- attachment is variable: alternate, opposite, basal or whorled
What are floral characteristics of Plantaginaceae family?
- flower perfects
- inflorescence variable
- 5-merous sympetalous flowers with two-parted corolla and obvious bilateral symmetry or almost radial symmetry and petal lobes of similar size (ex. linaria vulgaris)
- 4 stamens that attach to petal (some also have a 5th, non-functional stamen)
- ovary superior, syncarpous with 2 carpels and many ovules on axile placentae
What type of fruit does the Plantaginaceae family produce?
Capsule
What are some characteristics of the Plantago genus?
- small plants with basal leaves and spikes of small flowers
- main leaf veins are parallel
- flower 4-merous, sympetalous
- corolla dry and membranous
- 4 stamens with equal length, long filaments
- other traits are in common with other Plantaginaceae
What type of fruit does Plantago produce?
Circumscissile capsule (importnat for ID)
- has a dehiscence structure
What is the Lentibulariaceae family?
Bladderwort family
Diverse genera of aquatic insectivorous plants
What family is the Utricularia genus a part of?
Lentibulariaceae
What are some characteristics of Linaria vulgaris?
Didynamous stamens
3 petals fused into a lower and 2 petals fused into an upper lip (zygomorphic)
Ovary with 2 fused carpels with axile placentation
What is the difference between Utricularia and Plantaginaceae flowers?
Utricularia only has 2 stamens
Apart from this, flower morphology is the same
- flowers perfect
- 5-merous
- two parted corolla
- bilateral symmetry
- ovary superior
What are some distinctive characteristics of Utricularia?
Distinctive, very altered insectivorous leaves
- trigger hairs/absorptive hairs
What are uses of Lamiaceae (mint) family?
Diverse cosmopolitan family
Many culinary herbs
Essential oils
What are stem/leaf characteristics of Lamiaceae (mint) family?
- Herbaceous
- Square stems
- Opposite leaves
- Often aromatic
What are floral characteristics of Lamiaceae family?
- 5-merous sympetalous flowers
- flowers bilabiate or radial, in verticils (i.e. whorled arrangement in leaf axis) OR inflorescence spike-like
- 4 stamens attached to the petals by filaments
- 4-lobed ovary from 2 fused carpels, superior
What type of fruit does Lamiaceae produce?
Four 2-seeded nutlets
- it is a nutlet since seed coat stays fused
- also thicket than an achene
What family is the Fraxinus genus a part of?
Oleaceae (olive family)
What type of fruit does Fraxinus produce?
one-seeded samara
What are stem/leaf characteristics of Fraxinus genus?
- Dioecious trees
- Opposite, usually pinnately compound leaves
What are floral characteristics of Fraxinus genus?
- Perianth reduced to 4 tiny sepals or none
- 2 stamens per staminate flower
- 2 fused carpels with 2 ovules per carpel
What three families are we reviewing that are a part of the Solanales order?
Solanaceae
Convolvulaceae
Boraginaceae
Where is the Solanaceae (tomato) family found?
It’s habitat is quite widespread
Very diverse in American tropics, many adapted to disturbed habitats
What are leaf/stem characteristics of Solanaceae (tomato) family?
- Herbs, shrubs, and small trees or vines
- Alternate leaves
What are floral characteristics of Solanaceae?
- Flowers bisexual and radially symmetric
- 5 sepals, connate and persistent
- Superior ovary
- 5 petals, connate –> wheel, bell, or funnel shaped corolla often with distinct lines in the petals where they were folded in bud
Why is the Solanaceae family important?
Many important food plants (tomato, eggplant, potato)
Many poisonous species: alkaloids
What type of fruit does the Solanaceae family produce?
Berry or capsule fruits
What type of plants make up the Convolvulaceae (morning glory) family?
A family of vines
Sweet potato and some horticultural flowers
Some weeds
What is the Convolvulaceae family’s habitat?
Widespread, but most are tropical/subtropical
What are leaf/stem characteristics of the Convolvulaceae family?
- Twining vines
- Alternate leaves
- Leaves tiny, scale-like in Cuscuta
What are floral characteristics of Convolvulaceae?
- Sympetalous
- Funnel-shaped corollas, twisted in bud
- Perfect flowers
- Radially symmetric
- 5 stamens attached by filaments to petals
- 2 fused carpels, each with 2 seeds
- superior ovary
What type of fruit does the Convolvulaceae family produce?
Capsule fruits, 4-seeded
What is Cuscuta? Why is it distinctive?
Parasitic vine that inserts into host to steal water, mineral nutrients, and carbohydrates
- seedlings rotate until they find a host plant (or die)
- Haustoria feeding from host plant stem
Serious problem in fields grown for forage
Viral diseases are easily spread through Cuscuta
What is the Boraginaceae (forget-me-not) family’s habitat?
Widely distributed in tropical and temperate regions
What are stem/leaf characteristics of Boraginaceae family?
- Herbaceous
- Alternate, bristly leaves
What are floral characteristics of Boraginaceae family?
- Flowers in helicoid or scorpioid cymes
- 5-parted, sympetalous
- Superior ovary
- Radially symmetry
- Corolla often has appendages
- fornices
- 5 stamens attached by filaments to petals
- 4-lobed ovary (composed of 2 fused carpels) giving four 1-seeded nutlets in fruit
What type of fruit does Boraginaceae family produce?
Nutlets
What is tundra?
Biome where it is too cold for trees to survive
What are important factors for plant life in Arctic tundra?
Low precipitation, but also low evapotranspiration
Very cold temperatures in winter and cool to warm temperatures in summer
Strong winds
If average annual temperature is less than -2 degrees C, the subsoil will be frozen all year round –> permafrost
How is topography in tundra impacted due to cold?
Freezing and thawing and lack of water infiltration lead to unique patterns of shallow lakes and vegetated hills with ice cores (pingos)
What are pingos?
Small mountains formed from ice under the soil layer
How does permafrost impact topography?
Leads to unique land formations –> polygon development due to incomplete freezing and thawing of ice
How does differential time of spring lead to unique land formations?
Rivers flow north, so upstream areas thaw before downstream areas –> the result is ice dams and diversion of flow
What are the three main ecosystems in the tundra biome?
Mires
Tundra
Barrens
What does mire refer to?
general term for arctic wetlands, peat forming and underlain permafrost
What does tundra ecosystem refer to?
vegetation dominated by graminoid species, or erect or prostrate shrubs, underlain by permafrost
What do barrens refer to?
Areas with very sparse vegetation
On mountain sides, extremely cold and windy locations, other rocky areas
What are the main stresses experiences by tundra plants?
Cold
Desiccation (drying out)
Low nutrient availability
Very short growing season
Lower insect pollinator diversity (no bees for example)
What are main adaptations of tundra plant in response to environmental stresses?
Short (protection by snow)
Evergreen leaves
Perennial
Cushion growth form common
Vegetative reproduction is important
- asexual seed production, selfing, very common
What are examples of arctic families of plants?
Salicaceae, Gentianaceaem Polygonaceae, Saxigragaceae, Cyperaceae, Caryophyllaceaem Ericaceae, Fabaceae, Ranunculaceae, Rosaceae, Asteraceae, Brassicaceae, Poaceae
How is climate change impacting tundra biomes?
It is projected that for much of the boreal and tundra biomes, there will be a reduction in snowfall
Wildfires projected to become more frequent
Species might move north, but there are already communities of plants in these regions
- ex. expansion of beavers might have an impact on native arctic species
