Glossary¹|²|³

abaxial - surface of leaf away from the axis = convex surface

adaxial - surface of leaf nearest axis = concave surface

anterior - (of leaf) adaxial surface

antheridium - stalked oval organ producing male gametes

antheridial branch - branch bearing antheridia

archegonium - Female reproductive organ: a bottle-shaped structure containing the oosphere (female gamete) which, when fertilized, produces the sporophyte

archegonial branch - branch bearing archegonia

arcuato decurved - arched and bent downwards

areolation - pattern of cells as seen in surface view

autoecious - with antheridial and archegonial branches on separate stems of the same plant

blanket bog - Ombrotrophic bog where peat forms a broad ‘blanket’ over gently sloping or rolling ground, largely independent of local depressions

bog - Ombrotrophic peatland where the surface receives water and nutrients almost entirely from precipitation and airborne inputs; typically acidic, nutrient-poor and often dominated by Sphagnum and dwarf shrubs

border - (of a leaf) margin consisting of a row or rows of prosenchymatous cells

bract - modified leaf surrounding antheridium or archegonium

capitulum - Small head; in Sphagnum, a compact cluster of young branches at the top of the gametophyte stem

chlorocyst - Narrow, photosynthetic cell between hyaline cells in a Sphagnum leaf

clavate - club-shaped: narrowed towards the base and broader near the apex

comb fibril - lamella extending into the lumen of a branch leaf hyaline cell (in Europe only present in S. imbricatum complex (Sphagnum austinii and Sphagnum affine))

commissure - The contact line between a chlorocyst and a hyalocyst

commissural pores - pores lying along the commissures

concave surface - adaxial surface (of a leaf)

concolorous - of the same colour

convex surface - abaxial surface (of a leaf)

convolute - sheathing: rolled together

coronate - having corona: with a cup-shaped ring of leaves

cortex - outer layer or layers of stem or branch, consisting of comparatively large, thin-walled cells

crest - lamella

cucullate - (general) spoon shaped; oval and concave; (of leaves) hooded at the apex by incurving of the margins

dentate - toothed

dimorphic - having 2 forms

dioecious - with antheridia and archegonia on separate plants

efibrose - lacking fibrils (also efibrillose)

eporose - lacking pores

erect - with the distal end pointing towards apex of axis (used of branches or leaves)

erose - irregularly notched

eroded - worn away. Referring to the tips of the stem leaves, irregularly torn or notched

erecto-patent - Orientation of leaves or branches that stands between upright (erect) and spreading outward (patent), typically at a moderate angle from the stem

eutrophic - Wetland or water body with relatively high nutrient availability and productivity; in fens this is the nutrient-rich end of the gradient

evanescent - disappearing abruptly or quickly

exposure - (of photosynthetic leaf cells) reaching the surface of the leaf and not occluded by adjacent hyaline cells

fascicle - tuft or group of branches originating at the same point on a stem

fibrils - Microscopic, delicate, fiber-like structure found in Sphagnum leaves on the walls of hyalocysts or cortical cells; the fibrils are sometimes thickened inwards and then form partial partitions oriented, in general, transversely

fibrillose - bearing fibrils

fibrose - Alternative term for fibrillose, describing cells whose walls bear fibrils

flaccid - flabby; lying loosely and lacking stiffness

fruit - spore capsule and stalk

geotrophic - fed by groundwater

green cells - Common phrase for the narrow green photosynthetic cells (chlorocysts) between hyaline cells in a Sphagnum leaf

hanging branches - Informal description for the pendent branches in a fascicle that hang downwards and lie close or appressed to the stem

hyaline cells - General term for the large, empty, transparent water-storing leaf cells of Sphagnum, corresponding to the hyalocysts (also called leucocysts)

hyalocyst - Large, empty, transparent leaf cells in Sphagnum, specialized for water storage; also called hyaline cells or leucocysts

immersed - (of photosynthetic cells) enclosed by adjacent hyaline cells so that they do not reach the leaf surface

imperforate - without perforations; lacking pores or resorption gaps

incumbent - lying upon (of leaves lying closely along the axis and not spreading)

inflated - (of hyaline cells seen in cross-section) having a somewhat rounded or swollen shape

internal cylinder - central part of stem or branch consisting of, at least in the outermost layers, smaller, thicker-walled cells than the surrounding cortex

isophyllous - with stem and branch leaves of similar shape

lacerate - deeply divided into an irregular number of segments; appearing torn

lamella - elongated projection from the cell wall projecting into the lumen of a hyaline cell (seen only in S. imbricatum, in Europe)

lamellate - having lamellae

lanceolate - lance-shaped: tapering to a ± long point

leucocyst - Alternative name for a hyalocyst, the large, colourless water-storing cell in Sphagnum leaves

lingulate - tongue-shaped

lumen - cell cavity

lyrate - lyre-shaped: waisted

membrane gap - Term often used for a resorption gap, an irregular opening formed where part of a hyaline cell wall has been eroded

mesotrophic - Wetland or water body with intermediate nutrient status and productivity, between oligotrophic and eutrophic conditions

minerotrophic - Receiving water and dissolved minerals from groundwater or surface water that has contacted mineral soil or rock

mire - Wetland with at least some peat and living peat-forming plants; peat may be shallower than the depth often required to classify a site as peatland

monoecious - with archegonia and antheridia on the same plant, often on the same stem

oligotrophic - Wetland or water body with low nutrient availability and productivity; in peatlands this often applies to bogs and poor fens

ombrotrophic - Describes peatland surfaces nourished almost entirely by rain and snow, with little or no groundwater influence, leading to acidic, nutrient-poor conditions

ovate - egg-shaped: widest near the base and narrowed above

pallid - pale

papilla - Small bump or elongated projection on the inner wall of a hyaline cell that can give the cell a grainy appearance

papillose - Rough, with one or more small protuberances (papillae)

parenchymatous cells - ± hexagonal cells with end walls perpendicular to main axis

pectinate - comb-like

pendent branches - Branches in a fascicle that hang downwards and are ± appressed to the stem

perichaetium - female ‘inflorescence’: structure formed around the archegonium by modified leaves

perichaetial bracts - modified leaves surrounding the archegonium and forming the perichaetium

photosynthetic cells - cells containing chloroplasts

plano convex - (of hyaline cells seen in cross-section) having one outer wall almost flat and the other inflated or convex

pore - Complete opening through the wall of a hyaline or cortical cell, often visible as a round hole and sometimes occurring in rows

porose - having pores

posterior - (of a leaf) abaxial surface

prosenchymatous - elongated tapering cells lying parallel to the axis: not differentiated into hyaline and green cells

protonema - filamentous (sometimes thalloid) structure produced by germinating spore and giving rise to gametophyte (new stems), (plural protonemata)

pseudolacuna - triple pore formed at the junction of 3 hyaline cells (one basal and 2 upper lateral hyaline cell angles)

pseudopore - Thin or partially resorbed spot in a hyaline cell wall that resembles a pore but is not fully perforated; also called an imperfect pore by some authors.

quinquefarious - in 5 ranks

raised bog - domed ombrotrophic peat deposit

recurved - (of leaves) with the upper part curved back away from the axis

reflexed - (of leaves) bent backwards so that the apex points away from the axis apex

resorption - erosion or breakdown of parts of cell walls

resorption furrow - channel along the margin of a leaf, formed by erosion of side walls of the outermost cells

resorption gap - hole formed by erosion of part of hyaline cell wall (usually less regular in shape than a pore)

retort cell - large cell of stem or, more usually, branch cortex in which the distal end is perforated by a single pore; it is also often narrowed and turned outwards at the distal end

ringed pore - pore surrounded by a ring of thickened cell wall

rostrum - a beak (hence rostrate; with a beak)

scabrid - roughened: rather like a cheese grater

septate - having septa

septum - partition completely separating a hyalocyst, generally in the longitudinal direction (plural septa)

shadow pore - round or oval thinning of the cell wall of a hyaline cell (only revealed by heavy staining)

spatulate - paddle-shaped: narrowest at the base and wider above

spreading branches - Branches in a fascicle that, at least near their insertion, point upwards or outwards from the stem; longer branches can appear arched

squarrose - In reference to branch leaves abruptly bent or jointed nearly 90° backward at their distal end (see Sphagnum squarrosum, Sphagnum strictum)

subacute - acute but not sharply so

suberect - (of branches or leaves) with distal end pointing ± towards apex of axis

subsquarrose - (of leaves) with the upper part bent back abruptly, but not to quite the same extent as in squarrose examples

terete - rounded in cross-section: without ridges or angles

tetrahedral - shaped like a 3-sided pyramid

triradiate - having 3 limbs diverging from a central point

truncate - cut off abruptly at the distal end

tumid - swollen

ventral - (of leaf) concave or adaxial surface

vitta - a central band of cells in a leaf which are of different shape, size or colour from those on either side

acumen - A long, tapering point ending an organ

acuminate - Ending with a long point

acute - Refers to a leaf whose apex ends with a terminal angle less than 90 degrees

alternation of generations - Alternation between the haploid gametophytic phase (1n) and the diploid sporophytic phase (2n) during the life cycle of sexually reproducing organisms

antherozoid - The motile male gamete

apex - Point, tip or summit of an organ

ecogradient - Gradual change in environmental conditions, such as moisture or nutrients, across space, usually accompanied by predictable shifts in species composition

apical bud - Structure located in the centre of the capitulum which gives rise to all the organs; may be: obvious, visible but not obvious, prominent, conical or hidden among developing branches

apiculate - Ending in an abrupt point

appressed - Closely pressed or applied to the stem

ascending - Pointing or oriented obliquely upwards

attenuate - Of or pertaining to the tip of an organ which tapers; narrowly tapering

axil - The angle between the leaf and the bearing axis

axillary - Located in the axil of an organ, usually a leaf

biotope - Living environment describing the microtopographic habitat in which ecological conditions (temperature, water table level, chemical properties, etc.) are homogenous

branch - Is said of leaves inserted around the spreading or pendent branches. Traits of the leaves of the spreading branches are used to differentiate some species

branched - Bearing branches

calyptra - In Sphagnum, the calyptra is membranous and formed of remnants of the archegonia. It is minuscule and looks like a thin transparent layer overlying the operculum

capillarity - Phenomenon referring to the ability of water to rise naturally despite the force of gravity. In Sphagnum, this phenomenon is very important to hummock-forming species

capsule - Swollen part, topping the sporophyte, which contains the spores

carpet - Very soft peat surface dominated by bryophytes with sparse sedges, often from a few centimetres below to a few centimetres above the water table; footprints remain visible for a long time

chlorophyll - Green pigment found in the chloroplast, important for the absorption of light energy during photosynthesis

chlorophyllose - Referring or belonging to chlorophyll; specifically, a plant characterised by the presence of chlorophyll and by this fact coloured

chlorophyllous cells - Descriptive term for the green, chlorophyll-containing leaf cells of Sphagnum, equivalent to the chlorocysts between hyaline cells

complex - Grouping of very similar or related species

contiguous - In Sphagnum, refers to two adjacent cells with touching walls

cortical - Relating to the cortex

cushion - In Sphagnum, a small rounded tuft of individual mosses more or less erect and tightly clustered, all radiating

cuspidate - Ending abruptly in a strong, rigid point

denticulate - Finely dentate or with very little teeth

dichotomous - Branched in two; branching regularly into two branches; bifurcated once or more

distal - Far from the base or attachment point (as opposed to proximal)

falcate - Curved like the blade of a sickle or a scythe

fasciculated branches - Each fascicle normally consists of both spreading (divergent) and pendent (appressed to the stem) branches

fen - Minerotrophic peatland fed by groundwater or surface inflow from mineral soils, usually with sedges and brown mosses and little or sparse tree cover

poor fen - Fen with modest base and nutrient supply, chemically and floristically between ombrotrophic bogs and richer fens

intermediate fen - Fen with moderate base status and species richness, between poor and rich fens along the minerotrophic gradient

rich fen - Fen with relatively high base saturation and many calciphilous plants; chemically buffered and species-rich but not always strongly nutrient-rich

fimbriate - Fringed; having edges cut into a fringe

flark - Elongated, very wet hollow or mud-bottom pool in a patterned fen, usually waterlogged or flooded between slightly raised strings

flora - All the plants in a given area; also a volume describing each of these plants and used for their identification

foot - In Sphagnum, the swollen base of the sporophyte embedded in the apex of the pseudopodium; allows nutrient exchange from the gametophyte to the sporophyte

phenorigid - Describing a species whose visible form (size, colour and structure) changes little across different habitats or ecological conditions

free - On the walls of hyalocysts of Sphagnum leaves, is said of a pore not touching the walls of the contiguous chlorocysts

free pores - Pores in the centre of the hyalocyst and which, by this fact, does not come into contact with the walls of the adjacent chlorocysts

frequency - The degree of uniformity with which individuals of a species are distributed over a surface

gametophyte - Dominant sexual plant in mosses (therefore also in Sphagnum); leafy green plant generally haploid producing gametes by mitosis. The Sphagnum that we see in nature and which persist are gametophytes. The sporophyte has a very short life span on the leafy gametophyte.

habitat - The natural environment where an organism grows

herbarium - Permanent collection of plants that have been dried, identified, labelled and mounted on cardboard (vascular plants) or in envelopes (mosses including Sphagnum); also the location where they are stored (examples: the Louis-Marie Herbarium of Université Laval, the Marie-Victorin Herbarium of the Université de Montréal).

hollow - Lower, wetter depression between hummocks in peatland microtopography, ranging from firm lawns to very wet carpets or pools

hummock - Peat surface raised roughly 20–50 cm above the wettest level, often with drier Sphagnum, lichens and dwarf shrubs

hyaline - Without colour, transparent

hyaline cell - Singular of hyaline cells; a single large, empty, transparent water-storing leaf cell (a hyalocyst)

imbricate - Of or pertaining to branch leaves firmly inserted into each other and overlapping on the branch; overlapping each other like roof tiles

inner branches - Short, often erect branches in the centre of the capitulum

interfibrillose - Space between two fibrils

involute - Rolled inwards

label - Small data sheet glued to a herbarium sheet; the label presents various information regarding the specimen

lagg - Narrow minerotrophic fen or swamp belt around a bog, receiving water from both the bog and surrounding mineral soils and acting as a hydrological buffer

lawn - Nearly level peat surface with dense graminoids (grass like plants) and a diverse moss layer, usually about 5–20 cm above the water table and firm enough that footprints disappear quickly

lenticular - Lens-shaped; circular and doubly convex

margin - Edge of the leaf blade. May be even or entire, erose or fimbriate at the leaf apex and more or less enlarged near the base; also, the edge of a pond, marsh, etc.

minerotrophic peatland - Peatland receiving most water and dissolved minerals from groundwater or surface inflow that has passed through mineral soil; usually less acidic and more base-rich than ombrotrophic bogs. Fens are minerotrophic peatlands

mucronate - Of or pertaining to a leaf tip ending in an abrupt point

muskeg - North American term frequently used to designate a peatland. The word, of Algonquin origin

nomenclature - Method for naming plants based on international rules

obovate - Egg-shaped, with the broader part on the side of the apex

ovate-lanceolate - Leaf shape intermediate between ovate and lanceolate, broadly egg-shaped near the base but tapering into a longer, narrower tip

ombrotrophic peatland - Peatland whose water and nutrient supply come mainly from precipitation, giving chemistry and vegetation typical of bogs. Often functionally equivalent to a bog surface

operculum - A small lid closing the orifice of a capsule; opens explosively to release the spores in Sphagnum

outer branches - The outermost and longest branches of the capitulum

palustrine - Of marshes

peatland - Terrain covered by a layer of peat, usually at least 30–40 cm deep, built up under long-term waterlogged conditions and including bogs, fens and other peat-forming wetlands

pectinations - Thick projections clustered in a comb shape; pectinations are present on the cell walls of the branch and stem leaves

pendent - Apex pointed down the stem, when referring to stem leaves; also applies to delicate branches appressed to the stem

plicate - Forming many longitudinal folds

proximal - Near the base or attachment point (opposed to distal)

pseudopodium - Organ which is elongated or which elongates, functions as the seta and bears the sporophyte in Sphagnum

related - Of or pertaining to species very closely related phylogenetically, or with traits or origins in common

resorbed - Describes parts of cell walls that have been eroded or broken down by resorption, producing features such as resorption gaps or furrows

rhizoid - Filament, similar to a root, which has anchoring (to the substrate) and absorption functions in certain nonvascular plants

rhombic - More or less roughly diamond-shaped

rhomboidal - Longer than rhombic and oblong

ringed - Encircled by a thickened border; ring-shaped or forming a ring

scleroderm - In the stem, the scleroderma is the area underlying the cortex, consisting of layers of thick-walled cells. Synonymous: internal cylinder, stereome, sclerodermis

section - Taxonomic rank within the genus Sphagnum below subgenus and above species; currently only subgenus Acutifolia is divided into sections (Acutifolia, Insulosa, Polyclada), whereas older literature sometimes used “section” for what are now treated as subgenera

secund - Said of leaves all turned or pointing in the same direction

seta - In Sphagnum, the very short organ which bears the capsule; located between the capsule and the foot

soligenous - Is said of a peatland under the influence of a water supply external to the ecosystem that percolates or flows slowly through the peat surface

sp - Abbreviation for species, from the Latin species

sphagnologist - A person who is interested in the study of Sphagnum mosses

sphagnology - Botanical science particularly interested in the study of Sphagnum mosses

spiraled - Spiral-shaped, when referring to fibrils present on the walls of hyaline or cortical cells

spore - Microscopic corpuscule, most often spherical, almost always unicellular, produced in the capsule by reduction division and which produces the protonema upon germination

sporophyte - In Sphagnum and other mosses: plant body that produces spores and remains attached to the gametophyte; consists of a foot, a short seta and a capsule

snow-bed-vegetation - Plant communities occurring where late-lying snow persists into summer, producing short, cool and moist growing conditions on the ground

spp - Abbreviation for several species belonging to the same genus

spreading - Spreading or diverging from each other. In Sphagnum mosses, refers to branches inserted approximately 90° to the stem

stellate - Capitulum in which the outer and middle branches form a clear five-pointed star when viewed from above

stem - Belonging to or arising from the stem; said of leaves inserted directly on the stem. Stem leaf traits are used to discriminate between species: shape, length/width, apex, porosity, presence or absence of fibrils

subsecund - Leaves mostly curved toward one side, looking slightly one-sided but not as strongly as in fully secund leaves

systematics - Science focusing on the diversity of species and the relationships between them

taxon - Each of the classification levels of plants: kingdom, division, class, order, family, genus, species

taxonomy - Botanical discipline focusing on the classification, nomenclature and identification of plants

thallose - Development stage in nonvascular plants resembling a thallus

thermokarst - Periglacial phenomenon characterized by land subsidence due to the melting of permafrost

till - Unlayered deposit of gravel, boulders, sand and finer materials transported by a glacier

topogenous - Of a peatland forming in a topographic depression, with part of its water supply provided by the surrounding regional water table

window pores - Pores resulting from extensive cell wall resorption; much larger than other pores

cross section - cut made to an organ to show the internal structure

obtuse - Blunt; (opposed to acute)

ranked - Arranged in distinct rows or ranks (e.g., branch leaves appearing lined up in rows along the branch)

Sources

1. Ayotte, G., & Rochefort, L. (2020). Sphagnum Mosses of eastern Canada: Biology — Anatomy — Morphology — Herbarium conservation techniques and microscopic preparations. Editions JFD.
2. Daniels, R.E. & Eddy, A. (1990). Handbook of European Sphagna, 2. ed. HMSO, London. 284 s.