midterm 2 seed plants

Acacia collinsii

Tree in Costa Rica that has a mutualistic relationship with ants that sip the nectar from the petiolar nectary of a swollen thorn.

Accessory pigment

Light-absorbing compounds in leaves that work with chlorophyll to capture a wider range of light wavelengths.

Atropa belladonna

Deadly nightshade, extremely poisonous and contains toxic alkaloids, used cosmetically in the Victorian period.

Cataphyll

Reduced leaf for protection of the bud (new leaves as they form), resembles a scale and appears near the base of the shoot.

Fascicle

Bundles or cluster of leaves/needles that grow close together.

Fenestraria

Window plant, survive in the desert by burying itself in sand, exposing only tips of the leaf to the air.

Floral bract

Modified leaf that looks like flowers (ex: Poinsettia), helps attract pollinators.

Digitalis (Foxglove)

Flowering plant that contains a chemical (digitalis) used to treat heart conditions, is poisonous, grows in a rosette of leaves in the first year, then flowers and dies in the second.

Guard cells

Like 2 balloons, swell up to open the stomata or collapse on each other to close the stomata opening.

Gluttation

The process whereby excess water is exuded through hydathode, occurs at night or early morning when soil moisture levels and relative humidity are high.

Hydathodes

Microscopic pores in plants that release water droplets from leaves and excretes excess salts (also known as water pores).

Palisade mesophyll

Tightly packed cells for light absorption, 80% of chloroplast.

Palmately compound

A type of compound leaf where leaflets radiate from a single point, resembling the shape of a hand (ex: poison ivy).

Petiolar nectary

A gland on a plant's leaf petiole that produces nectar.

Petiolate leaf

Having a petiole or leafstalk attaching the leaf blade to the stem.

Pinnately compound

A leaf with leaflets that branch out from a central axis, or rachis, which functions like the midrib of the leaf.

Rachis

An extension of the petiole bearing leaflets.

Sessile leaf

No petiole, direct attachment to stem.

Spine

Sharp point for protection (ex: Cactus).

Spongy mesophyll

Loosely packed cells for gas exchange, can store oxygen between cells.

Tendril

Slender and used for support (ex: Sweet Pea).

Trichome or hair

Hair-like outgrowths of epidermal cells of leaves (ex: tomato).

Sun Leaves

Typically smaller, thicker, and more rigid, adapted to capture and process large amounts of sunlight efficiently but with a focus on reducing water loss.

Shade Leaves

Larger, thinner, and more flexible, adapted to capture light in low-light environments, but they are not as efficient in intense sunlight.

Horizontal Leaf Orientation

Maximizes light capture, especially in environments with diffuse or low light, as the broad surface is exposed to light.

Vertical Leaf Orientation

Helps reduce the exposure to intense midday sun, which is beneficial in hot, arid environments.

Vertical Leaf Orientation

Common in desert plants or those that grow in environments with high sunlight and limited water (e.g., succulents, some cacti).

Vertical Leaf Orientation

Minimizes heat absorption by reducing the area exposed to direct sunlight during peak hours.

Vertical Leaf Orientation

Reduces the risk of excessive water loss due to evapotranspiration, making them more water-efficient.

Petiole (Leaf stalk)

Flexibility: The leaf can move to maximize light capture or avoid excessive sunlight.

Petiole (Leaf stalk)

Better Air Circulation: Leaves on a petiole are less likely to overlap, allowing for better airflow around the plant.

Petiole (Leaf stalk)

Ease of Movement: Petiole allows leaves to adjust orientation based on changing sunlight and weather conditions.

Petiole (Leaf stalk)

Protection: The petiole can position the leaf in a way that it avoids physical damage.

Sessile (No petiole)

Stronger Attachment: Leaves are more securely attached to the stem, which can be beneficial in areas prone to strong winds.

Sessile (No petiole)

Water Conservation: There is no energy or resources spent on the development of a petiole.

Sessile (No petiole)

Reduced Vulnerability: Less prone to damage from herbivores or environmental stress.

Sessile (No petiole)

Compact Growth: Often found in plants that are adapted to grow in compact, dense environments.

Storage

Some leaves store water or nutrients to help the plant survive harsh conditions. Example: Onion (Allium cepa).

Defense

Some leaves are modified into spines to reduce water loss and deter herbivores. Example: Cactus (Opuntia sp.).

Carnivory

Certain plants have leaves modified into traps to capture and digest insects for additional nutrients. Example: Venus flytrap (Dionaea muscipula).

Hot, Dry, Exposed Environments

Plants in these conditions often have vertically oriented leaves or reduced leaf surface area to minimize direct exposure to intense sunlight.

Forest Understorey

Plants growing in low-light environments typically have horizontally oriented leaves to maximize light capture.

Conifer Needles Adaptation

Thick cuticles and sunken stomata to reduce water loss.

Aril

Fleshy, brightly coloured tissue covering of some seeds that develop from the ovule stalk, found in some conifers (ex: yew tree)

Carboniferous period

Golden age for plants, when the first seed-producing plant appeared, vast swampy forests dominated, near the end the climate cooled and glaciers formed

Cycadophyta

Division of gymnosperms, slow-growing, long-lived, and toxic plant group from the Mesozoic era, have palm-like leaves, dioecious reproduction, cone seeds, and nitrogen-fixing symbiosis.

Elkinsia polymorpha

Fern-like plant thought to be the oldest known gymnosperm, occurs in late Devonian

Ephedra

Gnetophyta genera, the sole genus in Ephedraceae, is a dioecious, joint-stemmed shrub or vine with reduced scalelike leaves, thriving in arid regions and valued for its ephedrine content.

General Sherman

Giant sequoia known as the largest tree by volume

Ginkgophyta

A slow-evolving 'living fossil' from the Permian, is a dioecious tree with fan-shaped leaves, motile sperm, and medicinal properties, with Ginkgo biloba as its sole surviving species.

Ginkgo biloba

Sole surviving species in Ginkgo genus, found in the wild only in China but cultivated worldwide, remained unchanged for around 80 million years.

Gnetophyta

The most advanced gymnosperms, are diverse tropical plants with angiosperm-like traits, efficient water transport, and possible early insect pollination, but have an unclear fossil history.

Gnetum

Gnetophyta genera, the sole genus in Gnetaceae, consists of tropical evergreen trees, shrubs, and vines with broad, leathery, angiosperm-like leaves, thriving in rainforest environments.

Larix lyallii

A deciduous conifer that is the treeline found at high elevations in the Rocky Mountains and Cascade Range which is not common for a deciduous tree to be a treeline species.

Megaspore

Female gametophyte/spores that will develop into ovules.

Microspore

Male gametophyte/spores that will develop into pollen grains.

Mormon tea

Common name for Ephedra.

Pinophyta

Diverse, stress-tolerant gymnosperms with needle- or scale-like leaves, wind pollination, and woody stems, primarily using tracheids for water transport and structural support.

Pinus longaeva

Methuselah, (Great Basin bristlecone pine), oldest individual tree

Tracheids

Microscopic, lignin-reinforced, dead-at-maturity cells that form water-conducting pipelines in gymnosperms and angiosperms, providing both transport and structural support.

Transfusion tissue

Composed of parenchyma and tracheids, recaptures water and nutrients from the xylem, facilitating exchange between vascular tissue and mesophyll.

Welwitschia mirabilis

A dioecious desert plant, has a woody disk, two tattered straplike leaves, a shallow root system, and uses CAM photosynthesis for water conservation.

Zamia

Genus of the cycad plant that includes the Zamia furfuracea.

Gymnosperms

Seed-producing plants that do not form flowers or fruits, classified into four major groups: Cycadophyta (Cycads), Ginkgophyta (Ginkgo), Coniferophyta (Conifers), and Gnetophyta (Gnetophytes).

Gymnosperms

A diverse group of seed plants that produce naked seeds and exhibit vascular tissue.

Naked seeds

Seeds that are not enclosed in a fruit.

Vascular tissue

Tissue composed of xylem and phloem for transporting water and nutrients.

Perennial lifecycles

Lifecycles that last for multiple years, typical of woody plants.

Alternation of generations

A reproductive cycle where the dominant sporophyte generation alternates with a gametophyte generation.

Cycads

A group of gymnosperms with palm-like leaves, dioecious reproduction, and flagellated sperm.

Ginkgo biloba

The only living species of Ginkgophyta, known for its fan-shaped leaves and fleshy seeds.

Conifers

The largest and most diverse gymnosperm group, characterized by needle-like leaves and woody cones.

Gnetophytes

A distinct gymnosperm group with three genera: Ephedra, Gnetum, and Welwitschia, featuring vessel elements.

Dioecious

Plants that have separate male and female individuals.

Monoecious

Plants that have both male and female reproductive structures on the same individual.

Flagellated sperm

Sperm that actively swim to the egg, found in cycads and ginkgo.

Non-flagellated sperm

Sperm that do not swim, found in conifers and gnetophytes.

Fleshy seeds

Seeds that have a fleshy outer layer, produced by ginkgo and some gnetophytes.

Vessel elements

Specialized cells in xylem that facilitate water transport, found in gnetophytes.

Insect pollination

Pollination that involves insects, observed in some cycads and gnetophytes.

Angiosperms

Flowering plants that produce seeds enclosed in fruits.

Living fossils

A term often used to describe cycads due to their ancient lineage.

Temperate habitat

The environment where ginkgo is commonly found.

Tropical and subtropical habitat

The environment where cycads are typically found.

Cold climates

The environment where many conifers are adapted to thrive.

Arid/semi-arid habitat

The environment primarily inhabited by gnetophytes.

Hyperion

Tallest tree (costal redwood)

Around 4,800 to 5,000 years old

Methuselah age

379 feet or 116 m

Hyperion height

56,186 cu ft

General Sherman volume

275 ft

General Sherman height

36 ft

General Sherman diameter (base)

109 ft

General Sherman Circumference (base)

17.5 ft

General Sherman trunk diameter at 60 ft

600,000

General Sherman board feet of lumber

120

General Sherman avg size houses built

1400 tons

General Sherman trunk weight

15 adult blue whales or 10 diesel locomotives

General Sherman equivalent