Annual
The thallus survives more than 1 month but less than 1 year.
Autumn
The thallus can be observed in autumn.
Blooming
Episodes of intense growth and mass proliferation of a macroalgal population (eg. green-tide of Ulva spp.)
Branched
A thallus forming lateral branches (and branchlets) from the main axis.
Calcareous Articulated
Segmented thallus that is encrusted or impregnated with lime.
Calcareous Non-articulated
Non-segmented thallus that is encrusted or impregnated with lime.
Calcareus
A thallus chalky, pertaining to lime, limy, or chalk-white.
Guiry M.D. and Guiry G.M., 2018.
Canopy
A thallus forming a true shade-canopy.
Carposporophyte Generation
In florideophycean red algae, the minute "parasitic" plantlet formed on the female gametophyte after fertilization.
Guiry M.D. and Guiry G.M., 2018
Cartilagineous
Thallus of firm texture, not soft, flexible and springy.
Sue Hiscock (1986), A field key to the British red seaweeds (Rhodophyta).
Compressed
A thallus partially but not completely flattened; cross section larger in one dimension than the other.
Crustose
A thallus crust-like and growing as a thin fleshy or calcified layer against the substratum; therefore often referred to as a fleshy or calcified crust; also a term used to describe a nongeniculate coralline thallus that is more or less flattened and horizontally expanded, is not taeniform, and has readily recognizable dorsal and ventral surfaces (based upon the Latin word crusta (crust)
Guiry M.D. and Guiry G.M. (2018)
Cystocarp Fertility
In florideophycean red algae, the number of tetrasporophyte recruits in year t+ 1 divided by the number of cystocarps produced in year t.
Engel et al., 2001 doi:https://doi.org/10.1046/j.1365-2745.2001.00567.x
Cystocarp Production
In florideophycean red algae, the average number of cystocarps in a cm3 of thallus (assuming a branch diameter of 1 mm), multiplied by the total volume of the female individual.
Engel et al., 2001
Demographic Trait
The quantitative traits of populations with reference to their size, density, distribution, and other vital statistics.
Dendroid
Arbuscular
A thallus having the shape or characteristics of a tree.
Digenetic
A morphological life history with two generations occurring, either diploid or haploid, and two types of organisms (gametophyte & sporophyte).
Digenetic diplohaplophasic heteromorphic
A life history having two generations (diploid and haploid) that are heteromorphic.
Guiry M.D. and Guiry G.M., 2019
Digenetic diplohaplophasic isomorphic
A life history having two generations (diploid and haploid) that are isomorphic.
Diplontic
A life cycle characterized by a diploid adult stage producing haploid gametes by meiosis, the zygote forming by fusion of a pair of gametes.
Lincoln et al., 1998
Discoid
A thallus forming a flattened disc with a rounded outline.
Encrusting
Flattened corticated thalli forming crusts strictly attached to the substratum.
Balata et al. (2011).
Balata et al. 2011
Ephemeral
The thallus survives only a few weeks, less than 1 month.
Epiphyte
Plants (algae) growing on top of other plants (algae) in a non-parasitic relationship.
Erect
A thallus extending upright from the substratum.
Fecundity
The total number of offspring (i.e. spores) produced either by an individual or by a population of a species in the given time period (i.e. a month, a year, etc.)
Engelen & Santos (2009) doi:10.1111/j.1365-2745.2009.01501.x Santos & Duarte (1996) doi: 10.1007/978-94-009-1659-3_31
Filamentous
A very fine thallus, hairlike.
Filamentous Pluriseriate
A filament formed by a line/chain of cells, two or more cell wide
Balata et al., 2011
Filamentous Uniseriate
A filament formed by a single line/chain of cells joined at their walls
Flat
A thallus having a generally flattened appearance, no protuberances and a low horizontal habit of growth.
Fleshy
Succulent algal forms, relatively thick, soft and smooth in texture; pulpy.
Diaz-Pulido, G. and McCook, L. July 2008, ‘Macroalgae (Seaweeds)’ in Chin. A, (ed) The State of the Great Barrier Reef On-line, Great Barrier Reef Marine Park Authority, Townsville.
Foliose
A thallus bearing leaves or leaf-like structures; having the appearance of a leaf.
Functional Trait
Any morphological, phenological or physiological trait, which impacts organism fitness.
Gametophyte Generation
The haploid generation (phase) in a plant's life-cycle of that produce sexual organs (gametangia)
Gelatinous
Thallus with jelly-like texture.
Generation Type
One of the two or more phases in the life history of a plant.
Guiry M.D. and Guiry G.M. (2018).
Globose
A thallus approximately spherical, ovoid or globular.
Brusca, 1980
Growth Rate
An increase in size and volume of the thallus.
Hurd et al., 2014
(g/L)/T
Haplodiplontic
Both haploid and diploid forms, with gametophytes giving rise to haploid gametes, and sporophytes giving rise to haploid spores by meiosis.
Haplontic
A life cycle in which meiosis occurs in the zygote to produce the haploid phase but in which only the zygote is diploid.
Haplostichous
In brown algae, an erect uniseriate filament.
Heteromorphic
Life cycle where the gametophyte and sporophyte generations are morphologically different.
Guiry & Guiry (2019)
Isomorphic
Life cycle where the gametophyte and sporophyte generations are morphologically similar.
Lanceolate
A thallus lance shaped and usually elongate.
Leathery
Thick and tough thallus.
Life History Trait
Traits that describe the life history characteristics of a species (eg. morphological and cytological traits, reproductive strategies, etc.).
Long Perennial
The thallus or part thereof with a lifespan exceeding 3 years.
Macroalgae Trait
Any measurable or observable characteristic related to macroalgae species.
Maximum Thallus Diameter
The diameter of the main thallus, when the shape is not foliose.
Maximum Thallus Length
The distance from the holdfast to the longer blade or axis.
Membranous
A thallus like a very thin sheet, usually translucent, somethimes with a texture almost like a polythene bag.
Monogenetic
A morphological life history in which only one generation occurs, either diploid or haploid.
Monogenetic Diplophasic
A life history having one morphological generation that is diploid with gametic meiosis.
Monogenetic Haplophasic
A life history having one morphological generation that is haploid with zygotic meiosis.
Monosiphonous
Thallus axis made up a single row of cells. May also covered with small cortical cells.
Sue Hiscock (1986) A field key to the British red seaweeds (Rhodophyta)
Morphological Trait
Any measurable phenotypic characteristic (form and structure) of an organism, which is relatively simple to measure, easily observable and with a potentially well-defined relation to physiology and ecology.
Non-calcareous
Thallus not encrusted or impregnated with lime.
Nutrient-uptake Rate
Nutrient-uptake Capacity
The abilities of organisms to sequester nutrients from the substrate (eg. NO3 and NH4).
Button, 1998
μmol gr-1 h-1
Perennial
The thallus survives for three or more years, usually becoming reproductive in the second and subsequent years.
Phases Alternance
Alternation of cytological generations during the life history of a plant.
Phases Resemblance
Morphological resemblance of the generation type in the life history of a plant.
Phenological Trait
A growth and development trait which is the timing of the occurrence of organism structure development stages and the relevant biological processes.
Phenotypic Plasticity
The capability of a genotype to change its phenotype according to prevailing environmental conditions.
Bijlsma, R. and Loeschcke, V. (2005), Environmental stress, adaptation and evolution: an overview. Journal of Evolutionary Biology, 18: 744-749. doi:10.1111/j.1420-9101.2005.00962.x
Photosynthetic Ability
The photosynthesis ability (TO:0000316) determined by measurements on photosynthesis, pigment content or the content and composition of enzymes associated with photosynthesis of a plant or of the plant part under stress.
Photosynthetic Rate
The total amount of carbon fixed by the plant per unit time and measured by determining the changes in CO2 concentration over a plant leaf in a glass enclosure.
Photosynthetically Active Radiation
PAR
The number of moles of photons in the radiant energy between 400 nm and 700 nm received by a surface for a specified amount of time during the photosynthesis process.
Hurd et al (2014) Seaweed ecology and physiology
mol photons m-2 s-1
Physiological Trait
Any trait involving biochemical processes consistent with the normal functioning of an organism.
Pinnate
Thallus with lateral segments alternate or opposite arranged along each side of an axis or branch; their arrangement is feather-like.
Polysophonous
Thallus axes in cross-section consisting of a central cell surrounded by a number of pericentral cells.
Sue Hiscock (1986) A field key to the British red seaweeds (Rhodophyta).
Polystichous
In brown algae, an erect filament, wich is uniseriate at the apex and became pluseriate below, by vertical and transverse divisions.
Population Density
The number of conspecific individuals in a given area or volume.
Guiry M.D. and Guiry G.M., 2018 doi:
Prostrate
Thallus trailing on the substrate.
Pseudoperennial
Deciduous perennial
The equivalent of a herbaceous perennial on land, with the majority of the plant dying back during an adverse season and regenerating later from a residual basal (often cryptic) remnant.
Reproduction
The development of one or more new organisms from the whole or from part of the protoplasm of a parent organism.
Respiration Rate
The total amount of carbon lost metabolically by the plant per unit time and measured by determining the increase in CO2 concentration over a plant leaf in a glass enclosure.
mm3 g-1 min-1
Seasonal Annual
An annual plant occurring during a specific season of the year, such as the winter or spring.
Short Perennial
The thallus or part thereof with a lifespan exceeding 1 year but under 3 years.
Siphonous
Tubular structure with multinucleate cells without cross walls except when reproductive bodies are formed.
Lee (2008), Phycology.
Sporophyte Generation
The diploid generation (phase) in a plant's life-cycle that produces spores [based upon the Greek, sporo (spore) & -phyte (plant)].
Spring
The thallus can be observed in spring.
Sub-canopy
A thallus forming a secondary cover, usually of 20 cm height maximum.
Summer
The thallus can be observed in summer.
M. Robuchon (pers. comm.)
Surface Area
The total area that the surface of the thallus occupies. Surface area estimation methods involving colorimetry, image analysis and physical measurement of leaf area.
Armstrong et al., 2003
Surface Area-Volume Ratio
SA-V
The ratio between the surface area and volume of an organism.
Survival Strategies
Adaptive features of function, structure and reproduction that enhance growth and survival.
Terete
Cylindrical thallus, round in cross-section.
Tetrasporophyte Generation
In red algae, the diploid generation responsible for producing tetraspores [based upon the Greek, tetras (four), sporo (seed) & phyton (a plant)].
Thallus Dry Weight
The weight or mass of organic matter after removal of water by heating to constant weight.
Thallus Fresh Weight
The weight of the thallus after it was washed with tapper water and dried gently with soft paper towel to remove any free surface moisture.
Thallus Life Cycle
The sequence of nuclear and morphological phases of the thallus.
Thallus Life Span
The structural features, the resting stage nature and duration of life of seaweeds, resulting from the interaction of all life processes, both genetic and environmental.
Thallus Seasonality
The occurring season of a species.
Thallus Shape
The approximate 3 dimensional shape of a thallus.
Thallus Size
Morphological characteristic, easy to measure, related to the overall physical magnitude of an organism, comparable across taxa and extremely variable through time and space.
Schmidt et al. 2006 doi:10.1016/j.earscirev.2006.05.004
Thallus Texture
The tactile surface characteristics and appearance of a thallus.
Thallus Vertical Space Used
The vertical projection of the thallus relative to the substrate.
Thallus Volume
The volume (in millilitres) of an algal thallus measured by placing the alga in water and determining the volume of water displaced.
Hacker and Steneck, 1990
Thallus Weight
Any measurable characteristic related to the thallus weight.
Thallus Wet Weight
The weight of the thallus obtained after external fluid removal on filter paper.
Tissue C/N Ratio
The ratio between Carbon and Nitrogen contained in plant tissues.
Tissue N:P Ratio
The ratio between Nitrogen and Phosphorus contained in plant tissues.
Hurd et al (2014)
Total biomass
The amount of living matter in an area.
g/m2
Trait
Any measurable or observable characteristic of an organism.
Trigenetic
In florideophycean red algae, a morphological life history with three types of morphological generations (gametophyte, carposporophyte & tetrasporophyte) and two cytological phases (diploid & haploid).
Tubular
Macroscopic thalli consisting of 1- or few-layered hollow tubes.
Turf
Primary space holders with limited vertical height, usually ~ 5 cm height.
Winter
The thallus can be observed in winter.