Botany Exam Review: OCBILs, Fire Adaptations, Parasitism, and Floral Terminology

Comprehensive vocabulary flashcards covering OCBIL ecology, nutrient acquisition adaptations, fire interaction strategies, parasitic and carnivorous plant biology, and botanical terminology.

OCBILs

Old, Climatically Buffered, Infertile Landscapes; ancient, slowly eroding landscapes that have remained climatically stable for long periods, characterized by highly leached, nutrient-poor soils, high species richness, and localized rare endemics.

YODFELs

Young, Often Disturbed, Fertile Landscapes; dynamic ecosystems characterized by fertile, unweathered soils, frequent disturbances, variable and extreme climates, low species richness, and high productivity.

Cluster Roots

Specialised clusters of closely spaced rootlets that emerge from lateral roots in response to low phosphorus, releasing carboxylates (such as citrate and malate) to lower soil pH and mobilise bound phosphate.

Endomycorrhizas

Symbiotic fungal associations in which fungal hyphae penetrate the cell walls of plant roots, producing an internal interface that facilitates the bidirectional exchange of nutrients, water, and carbohydrates.

Ectomycorrhizas (ECM)

Symbiotic fungi that encase plant roots in an external mantle or sheath without penetrating the interior of the cortical cells.

Actinorhizal Plants

Plants that establish nitrogen-fixing root symbioses with filamentous actinobacteria (genus Frankia), exemplified in Western Australia by Allocasuarina.

Pitfall Trap

A hollow, vase-like modified leaf trap filled with digestive fluids or bacteria that drowns and digests insects, found in genera such as Cephalotus and Nepenthes.

Flypaper Trap

A carnivorous leaf trap covered in glandular trichomes that secrete adhesive mucilage to capture prey, found in Drosera, Pinguicula, and Byblis.

Snap Trap

An active carnivorous leaf mechanism that closes rapidly via touch-sensitive trigger hairs to entrap prey, characteristic of Dionaea and Aldrovanda.

Bladder Trap

A hollow, underwater or subterranean trap mechanism that generates an internal vacuum to actively suck in aquatic invertebrates, found in Utricularia.

Lobster-Pot Trap

A passive carnivorous leaf trap lined with inward-pointing hairs that guide prey irreversibly toward digestive enzymes, found in Sarracenia psittacina and Darlingtonia californica.

Haustorium

A specialised morphological organ formed by parasitic plants that penetrates host tissues to access the vascular system and withdraw water, minerals, or photosynthates.

Holoparasite

An obligate parasitic plant lacking chlorophyll that is entirely dependent on its host for all water, minerals, and organic nutrients.

Hemiparasite

A parasitic plant that retains functional chlorophyll and photosynthetic capacity while extracting water and dissolved minerals from a host via haustorial connections.

Stem Parasite

A parasitic plant that attaches directly to the aerial stems and branches of a host tree or shrub, such as the mistletoe Amyema preissii.

Root Parasite

A parasitic plant whose haustoria connect directly to the underground root system of host plants, exemplified by Nuytsia floribunda.

Pilostyles

A genus of endophytic stem holoparasites that lack roots, stems, and vegetative leaves, existing as cellular strands within host secondary phloem until emerging through bark to flower.

Resprouter

A fire-adapted plant that survives above-ground fire damage by regenerating vegetative shoots from protected subterranean lignotubers or epicormic buds insulated under thick bark.

Obligate Seeder

A plant species killed outright by severe fires that relies entirely on a persistent soil seed bank stimulated by heat or smoke to regenerate.

Lignotuber

A swollen, woody subterranean structure packed with dormant buds and nutrient reserves that enables post-fire vegetative resprouting.

Epicormic Buds

Dormant vegetative buds buried beneath the bark of a tree trunk or branch that activate to produce new leafy shoots after the canopy is consumed by fire.

Fire Ephemerals

Short-lived plants whose dormant soil-stored seeds require seed burial and after-ripening before germinating in profusion in response to fire cues such as smoke and heat.

Acacia-Triodia Line

A phytogeographic boundary across Australia dividing the northern zone dominated by tropical summer rainfall from the southern zone characterised by mesic winter rainfall.

Dioecious

A plant reproductive system where staminate (male) and carpellate (female) flowers are borne on separate individual plants.

Monoecious

A plant reproductive condition where distinct male and female flowers are produced on the same individual plant.

Dichogamy

A floral adaptation that limits self-pollination through the temporal separation of male (stamen) and female (carpel) reproductive maturity.

Endozoochory

The dispersal of plant diaspores through internal passage via animal ingestion and subsequent defecation.

Synzoochory

The deliberate collection, transport, and dispersal of seeds using animal mouthparts, often associated with seed caching or hoarding.

Epizoochory

The passive, external dispersal of diaspores via spines, barbs, or sticky coatings that adhere to the fur, feathers, or extremities of animals.

Flower Morphology

The structural organization of an angiosperm blossom consisting of perianth elements (sepals and petals), the stamen (filament and anther producing pollen), and the pistil (stigma, style, and ovary enclosing ovules).

Actinomorphic

A flower displaying radial symmetry, capable of being bisected into two identical halves along multiple radial planes.

Zygomorphic

A flower displaying bilateral symmetry that can only be divided into mirror-image halves along a single vertical plane.

Amphistomatous

Possessing functional stomata distributed across both the upper and lower surfaces of a leaf blade.

Epistomatous

Having stomata positioned exclusively on the upper (adaxial) surface of a leaf blade.

Hypostomatous

Having stomata confined solely to the lower (abaxial) epidermis of a leaf.

Stomatal Crypt

A sunken invagination in the leaf epidermis containing stomata, functioning as an adaptation to minimize transpirational water loss in arid environments.

Andromonoecious

A plant breeding system where both hermaphrodite (bisexual) and staminate (male-only) flowers occur on the same individual plant.

Betalain

A class of tyrosine-derived red and yellow pigments found exclusively in plants belonging to the order Caryophyllales, replacing anthocyanins.

Cladode

A flattened, photosynthetic shoot or branch that assumes the morphology and physiological role of a foliage leaf.

Phyllode

A flattened, expanded petiole that carries out photosynthesis when true leaf blades are reduced or absent, common in Australian Acacia species.

Column (Gynostemium)

A composite floral organ formed by the complete fusion of the stamens, style, and stigma, characteristic of families such as Orchidaceae and Stylidiaceae.

Decussate

An opposite phyllotaxy where each successive pair of leaves is oriented at right angles ($90^\circ$) relative to the pair below it.

Didynamous

An androecium composed of four stamens arranged in two pairs of unequal length, with two long stamens and two short stamens.

Extrafloral Nectary

A specialised nectar-producing glandular structure located on vegetative organs outside the flower, primarily functioning in mutualistic defense by attracting predatory insects.

Hypanthium

A cup- or tube-shaped floral structure formed by the basal fusion of the sepals, petals, and stamens, surrounding or enclosing the ovary, common in Myrtaceae.

Indusium

A cup-shaped or membranous outgrowth that encloses and covers the stigma in the family Goodeniaceae.

Labellum

A modified, enlarged median petal in orchid blossoms specialized for attracting and positioning insect pollinators.

Lemma

The outer and lower of the two bract-like scales enclosing a grass floret.

Palea

The inner, upper bract positioned opposite the lemma within an individual grass floret.

Glume

One of the two sterile bracts found at the base of a grass spikelet below the individual florets.

Lodicule

One of two or three small, reduced scales at the base of a grass ovary that swell with water to push the lemma and palea apart during anthesis.

Revolute

A condition where the outer margins of a leaf roll or curl downwards toward the abaxial surface.

Staminode

A sterile, modified stamen that has lost the ability to produce functional pollen, often assisting in pollinator attraction.

Sympetalous

Having petals fused along their margins to form a united corolla tube.

Superior Ovary

An ovary positioned above the attachment point of the sepals, petals, and stamens, denoted in a floral formula as $\underline{G}$.

Inferior Ovary

An ovary positioned below the point of insertion of the perianth and androecium, denoted in a floral formula as $\overline{G}$.