Guide to Liverworts of Oregon: Glossary
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acuminate - 
leaf tip or lobe tip gradually and evenly narrowed to a slender, sharp point; not as drawn out as attenuate but sharper and more drawn out than an acute tip -- Example: Douinia ovata
acute - 
leaf tip or lobe tip with a point formed by sides meeting at an angle less than 90º not as slender a point as acuminate but sharper than obtuse -- Example: Douinia ovata
angular - 
refers to gemmae with points or high bumps; in this sense essentially synonymous with stellate -- Example: Lophozia hatcheri
androecium - 
a male shoot or portion of shoot formed by a series of male bracts; often quite different in appearance from sterile shoots -- Example: Chiloscyphus coadunatus
anisophyllous - 
a liverwort whose leaves are not all alike but have one row reduced in size or otherwise differing from the other two rows of leaves; a common condition Example: -- Calypogeia sphagnicola
antheridia - 
the sperm producing organs of plants; in liverworts the antheridia are nearly spherical and carried on a slender stalk ten or more cells long but only one or two cells wide || a single one is an antheridium -- Examples: Left, Chiloscyphus coadunatus; Right: Fossombronia incurva, arrows indicate antheridia
antical - 
essentially synonymous with dorsal; the upper side of a leafy liverwort shoot or the margin of a leaf on the side attached to the upper side of a stem. The opposite of postical. -- Example: Scapania bolanderi
appendage - 
a nonspecific term for a projecting part of an organ. -- Example: left, ventral scale with single scale appendage of Asterella bolanderi; right, scale appendage of Marchantia alpestris
appressed - 
leaves overlapping tightly and mostly parallel to the stem; essentially synonymous with imbricate but not necessarily overlapping; similar to julaceous but when appressed the leaf tips are not necessarily curved in and the leaves not necessarily wide and concave -- Example: Anthelia juratzkana
archegonia - 
the egg producing organs of plants; in liverworts the archegonia have no stalk but are rather squat and sessile with a slender neck || a single one is an archegonium -- Example: Fossombronia
ascending - 
plants growing away from the substrate; in contrast to prostrate -- Example: Metzgeria violacea
attenuate - 
leaf tip or lobe tip drawn out into a very narrow point, the sides not evenly narrowed but more stretched out towards the tip; more slender than acuminate -- Example: Chiloscyphus coadunatus
autoicous - 
having antheridial shoot segments on the same plant, separate from the female shoot segments, one of the three kinds of the monoicous condition. -- Example: Cephalozia bicuspidata
axillary - 
positioned in the angle between a leaf and the stem, on the side towards the stem; also in the angle between a bract and the stem; derived from axil, the technical term for armpit -- Example: Scapania americana showing antheridia in axil of a leafy bract
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bidentate -
with two distinct teeth at the end of a leaf; essentially synonymous with shallowly bilobed -- Example: Chiloscyphus coadunatus
bifid - 
cut into two; usually refers to bilobed leaves or underleaves with a deep sinus and narrow lobes -- Example: Herbertus aduncus
bilobed - 
a leaf or underleaf with two tips; the tips may be separated by a shallow or deep sinus -- Example: Marsupella bolanderi
botryoidal - 
looking like a cluster of grapes; in liverworts the term is used to describe oil bodies composed of a cluster of distinct globules, few enough (less than a dozen) and large enough that the number of globules can be easily counted with a 40X objective -- Example: Calypogeia azurea
bract - 
modified, often enlarged, leaf subtending a perianth or antheridium; if subtending antheridia called male bracts and if subtending a perianth called female bracts (but only if without antheridia). Note that if a shoot is paroicous, the bracts subtending the perianth are male bracts. -- Examples: left, Cephaloziella divaricata; right, Jamesoniella autumnalis
bracteole -
a modified, enlarged underleaf subtending the perianth in leafy liverworts; situated ventral to, and often fused to, the bracts; often present in plants where underleaves are otherwise lacking on sterile stems -- Example: Cephaloziella divaricata
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caducous - 
detaching from the plant early and readily due to the presence of a physiologically weakened point of attachment; may refer to leaves, perianths, shoot segments or any other vegetative part of the plant body which often function as vegetative fragments more-or- less equivalent to gemmae -- Example: Bazzania denudata
canaliculate - 
a leaf with the sides turned up making a trough or channel down the center of the leaf -- Example: Plagiochila porelloides
calyptra - 
structure derived from enlarging archegonia after fertilization; in liverworts it is seldom prominent except in the Metzgeriales, where it often forms a fleshy enclosure around the developing sporophyte -- Example: Metzgeria conjugata
carpocephalum - 
a structure derived from an offshoot of the thallus of a marchantoid liverwort which bears sporophytes elevated above the surface of the thallus. See also: Female - archegoniophore; Male - antheridiophore. -- Example: Asterella californica
cilia - 
hair-like projections consisting of strands of cells connected end-to-end || a single one is a cilium -- Example: Ptilidium californicum
complicate-bilobed -
a leaf with two lobes, one lobe folded over on the other-- Example: Scapania
compound pore - 
an epidermal pore that has the form of a short, barrel shaped chamber that projects down into the air space below -- Example: Marchantia alpestris
conspicuous - 
relatively easy to find by an experienced observer; when referring to underleaves it means that the underleaves are consistently produced, usually composed of 10 or more cells, and clearly visible near shoot tips under a 20X hand lens -- Example: Gyrothyra underwoodiana
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dentate - 
leaf margins with tooth-like projections, like a dog's jaw; if marginal teeth are more like a shark's jaw or a handsaw, the margin is serrate; when really finely toothed it is serrulate. -- Example: Cephaloziella turneri
distal - 
the outer side or the far side; the distal face of a spore is more or less hemispheric. When spores are formed, the distal faces are exposed on the outside of the tetrad cluster. The inner face of a spore is the proximal face. -- Example: Riccia glauca
dorsal - 
on the back or upper side, as a backbone or dorsal fin of a shark. In liverworts dorsal refers to the upper side of a shoot or thallus, facing away from the substrate; the side facing downwards being the ventral (belly) side. Rhizoids are typically found on the ventral side of a liverwort thallus or shoot. (The term is used differently in mosses and vascular plants, being applied to an individual leaf rather than the entire shoot; there dorsal refers to the side of a leaf facing away from the apex or stem.) --Examples: Left, Scapania bolanderi, dorsal and vental lobes of a leafy liverwort; right, Preissia quadrata, cross section showing dorsal and ventral sides of thallus.
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edentate - 
lacking teeth; the opposite of dentate; essentially synonymous with entire (The term edentate is most often used to describe plants which usually have dentate leaves.) -- Example: Jungermannia exsertifolia
elater - 
a slender cell with one or more spiral shaped thickenings, found mixed with spores in the capsules of liverwort -- Example: Fossombronia
emarginate - 
a truncate leaf tip that has a noticeable but shallow notch, not deep enough to call the leaf bidentate or shallowly bilobed; in most liverwort literature this term is essentially synonymous with retuse -- Example: Chiloscyphus profundus
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fasciculate - 
gemmae growing in bundles or tufts with a tightly branched base -- Example: Rivulariella gemmipara
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gametophyte - 
the dominant, usually perennial, life form of mosses and liverworts; in most mosses and many liverworts it is composed of a slender stem with distinct leaves but in some liverworts it grows as a thallose ribbon of fleshy tissue -- Example: Fossombronia pusilla
gemmae -
small packets of cells, one to a hundred or more cells per packet, produced by budding which can break off and be carried away to grow directly into new plants; asexual reproductive propagules of distinctive, regular shape; common in liverworts where they are few celled and produced on leaf margins or, less often, in specialized gemmae receptacles || a single one is a gemma -- Examples: ;
globular - 
liverwort oil bodies composed of relatively distinct, round segments or globules; too many (more than a dozen) to count accurately; coarsely globular to finely globular spans the range of oil body types between botryoidal and granulose -- Example: Jungermannia exsertifolia
granulose - 
liverwort oil bodies composed of numerous, tiny, barely discernable granules; in one direction verges towards finely globular, in a second to homogeneous, and in a third towards lumpy; in some literature this is called papillose because this type of oil body appears minutely bumpy -- Example: Lophozia ventricosa
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heterogeneous - 
Meaning of different form, in liverworts referring to oil bodies that are composed of globules of different sizes, in contrast to oil bodies of uniform texture (as used in Paton, 2000). -- Example: Calypogeia mulleriana
homogeneous - 
Of uniform structure, here referring to liverwort oil bodies that are of uniform texture; in contrast to heterogeneous oil bodies. This is the definition I prefer, as used in Paton (2000). Sometimes defined as liverwort oil bodies that are clear and glistening (as used by Schuster and many other authors), in contrast to granulose or lumpy oil bodies. -- Example: left, Nardia scalaris; right, Chiloscyphus profundus.
horizontal - 
in leafy liverworts, having leaves inserted nearly parallel to the axis of the stem; no regional species has truly horizontal leaf insertion -- Example: Chiloscyphus pallescens
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incubous -
with dorsal margins of leaves tilted up towards the tip of the shoot; in contrast to succubous, where the dorsal margins of leaves tilt down, away from the shoot tip -- Example: Frullania
inserted -
the mode of attachment; in liverworts the term is used to describe how a leaf is attached to the stem; e.g., oblique insertion, transverse insertion, etc.
intercalary - 
1) positioned below the apex, as an intercalary androecium. 2) the part of a stem between the leaves in a leafy liverwort; most often used to describe branches that are not derived from a part of a leaf. Contrasted with terminal branching, where a part of a leaf is replaced by a branch. -- Example: Hygrobiella laxifolia with lateral intercalary branch.
involucre - 
a sheath or flask-like structure that surrounds archegonia and developing sporophyte in a thallose liverwort; similar in function (and often form) to a perianth but derived from thallus tissue rather than leaves -- Example: Fossombronia pusilla
isodiametric - 
with length and width approximately equal; in contrast to elongated -- Example: Bazzania denudata isodiametric cells.
isophyllous - 
liverworts with three identical rows of leaves; not a common condition; see anisophyllous -- Example: Haplomitrium hookeri
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julaceous - 
a shoot that looks like a braided cord because the leaves are concave and tightly overlapping -- Example: Gymnomitrion coralloides
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lacerate - 
an edge or margin that has the appearance of being torn irregularly -- Example: Pellia endiviifolia involucre mouth
lanceolate - 
shaped like the head of a spear; a slender ovoid that is widest below the middle and 2-3 times longer than wide -- Example: Harpanthus flotovianus
lateral leaf - 
an unreduced leaf of an anisophyllous liverwort. When one of the three rows of leaves of a leafy liverwort are reduced, the two rows which are unreduced are lateral leaves; these are usually referred to simply as "leaves" while the leaves in the smaller row are called underleaves. -- Example: Chiloscyphus coadunatus
lateral intercalary branch - 
branches developed on the side of the stem between the lateral leaves; in contrast to postical intercalary branches -- Example: Bazzania ambigua (? might be lateral terminal branch)
lingulate - 
shaped like a tongue; an ovoid with sides that are straight and taper gradually to a blunt, rather wide point -- Example: Diplophyllum albicans leaf.
lobulate -
having a small lobe; posessing a lobule; see "lobule"
lobule - 
the small lobe of a leaf that has very unequal lobes; lobules are sometimes modified into cup-like or flask-like forms -- Example: Porella navicularis
lumpy - 
a translucent oil body that is composed of indistinct, amorphous lumps, neither granulose nor clear and homogeneous; with the appearance of translucent lumps of oatmeal porridge; there seems to be no comparable term in the literature -- Example: Bazzania ambigua
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marsupium - 
archegonium and/or sporophyte embedded in a bulbous, pouch like swelling on the ventral side of the shoot -- Example: Nardia breidleri
minute - 
leafy liverworts with average shoots less than 0.5 mm wide and whose largest shoots are 1 mm or less -- Example: Cephaloziella divaricata
monoicous -
with archegonia and antheridia located on the same plant; the three common monoicous types are autoicous, paroicous, and synoicous. No regional liverworts exhibit the synoicous condition. Synoicous mosses are frequent whereas few mosses are paroicous.
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nodose - 
In liverworts this refers to cell walls with fat, bulging, dimpled thickenings at the corners (trigones) -- Example: Herbertus aduncus
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oblique - 
leaves inserted at an angle to the axis of the stem; in between horizontal insertion and a transverse insertion -- Example: Chiloscyphus polyanthos
oblong - 
with a rectangular shape, the sides more or less parallel and hardly wider at base than near the tip -- Example: Chiloscyphus profundus
obtuse - 
an apex that comes to a blunt, shallowly angular point, the sides converging at an angle greater than 90°; essentially the same definition as in classical geometry -- Example: Anastrophyllum minutum
oil body - 
cellular inclusion found in many liverwort cells; usually several in each cell but sometimes numerous, solitary or absent; usually from as large to 2X the size of chloroplasts but sometimes nearly filling a cell; usually clear and colorless (when they look most like oil globules), occasionally dark brown and opaque; usually of characteristic number and form in a species and therefore useful for identification purposes; usually disappearing when a plants dries and dies. Examples: Left, Lophozia hatcheri; right, Jungermannia exsertifolia
ostiole - 
the "neck" from which sperm are released from antheridial chambers in the complex thalloid liverworts -- Example: Riccia beyrichiana
ovate - 
shaped like an egg, widest between middle and the base, about 1.5 - 2 X longer than wide -- Example: Jungermannia obovata
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paroicous - 
antheridia positioned immediately below or posterior to the archegonia; one of three common conditions classed as monoicous -- Examples: left, Jungermannia obovata; right, Mannia gracilis (see labels on enlarged image)
pellucid - 
colorless tissue that transmits light well, nearly transparent; usually applied to cells with thin walls, inconspicuous oil bodies, and few chloroplasts -- Example: Cephalozia lunulifolia
perianth - 
a tubular or flask-shaped structure in leafy liverworts inside which the archegonia are produced; typically at the tip of long shoots but sometimes at the end of short, lateral branches -- Examples: left, Cephaloziella divaricata; right, Marsupella emarginata
perigynium -
lower part of the perianth where the bracts are fused to it -- Example: Marsupella emarginata
pinnate - 
a branching pattern produced by regular side branches that diverge at right angles from the main stem, often arranged close enough to look like a feather -- Example: Kurzia sylvatica
plicate -
with longitudinal folds that look like pleats; used to describe perianths -- Example: Cephaloziella divaricata
postical -
essentially synonymous with ventral; the lower side of a leafy liverwort shoot or the margin of a leaf on the side attached to the ventral side of a stem. The opposite of antical. -- Example: Scapania bolanderi
prostrate - 
growing horizontally, pressed to the substrate; in contrast to ascending -- Example: Metzgeria violacea
proximal -
the inner side; the proximal face of a spore usually bears a trilete scar and three plane surfaces. When spores are formed, the proximal faces are on the interior of the tetrad cluster. The outer face of a spore is the distal face. -- Example: Riccia glauca
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recurved - 
leaf margin or leaf tip curling or bending back in a smooth, rather open curve; a very tight curl on a leaf margin is called a revolute margin -- Example: Porella navicularis
remote - 
leaves spaced apart on a stem so they do not overlap; the Cladopodiella illustrated at right has leaves so remote they might be described as distant -- Example: Cladopodiella fluitans
reniform -
shaped like a kidney, such as the scale appendage of Marchantia -- Example: Marchantia alpestris
retuse -
a truncate leaf tip that has a noticeable but shallow dip, not deep enough to call the leaf bidentate or shallowly bilobed; in most liverwort literature essentially synonymous with emarginate -- Example: Chiloscyphus profundus
revolute -
leaf margin curling back into a tight roll on the under side -- Example: Porella navicularis
rhizoid - 
the liverwort equivalent of a root hair, typically growing from the underside of liverwort stems; rhizoids are all alike in leafy and simple thalloid liverworts (first image at right) but of two types, smooth and pegged (second image at right), in complex thalloid liverworts -- Example: left Fossombronia pusilla, right Conocephalum conicum
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scattered - 
used to described rhizoids that grow more or less uninterruptedly along the underside of the stem; in contrast to tufted. Example: Cladopodiella fluitans
secund - 
turned to one side; a shoot with secund leaves looks as if the wind had blown the leaf tips so they all point in one direction -- Example: Herbertus aduncus
segment - 
one of the finger-like lobes of a leaf that is deeply divided -- Example: Blepharostoma trichophyllum
simple pore - 
An opening in the epidermis of a thalloid liverwort which provides passage to the air chambers below, without any elaboration of the margins beyond one or more encircling rings of differentiated cells -- Examples: left, Asterella bolanderi; right, Conocephalum conicum
sinus - 
the notch or low spot between two lobes of a leaf -- Example: left, Marsupella bolanderi
slime papilla - 
A pear shaped cell that is coated with mucilage when clustered to protect the growing tip of a thallus or shoot, sessile in leafy liverworts but usually stalked in thalloid liverworts -- Example: left, Cephaloziella divaricata, sessile papillae on underleaves and leaf bases; right, Pellia neesiana, stalked slime papillae under apical notch.
sporophyte - 
the spore producing part of a plant; in liverworts the sporophyte consists of the foot, which is embedded in the gametophyte and usually hidden from view, the seta, a stalk, and a capsule on the stalk. The capsule matures first, usually contained within the perianth or involucre. The capsule is elevated rapidly on a seta by thin walled cells that elongate when filled with water. -- Example: Fossombronia pusilla
stellate -
with projections in all directions, like a star with points rounded off; used to describe gemmae in liverworts; called angular or angulate in some literature; example is Lophozia hatcheri
succubous - 
leaves inserted at an angle so that when the stem tip is up, the leaves overlap like a venetian blind turned down
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terete - 
with a cylindrical form, having an isodiametric cross section; in contrast to compressed or flattened. Example: Lophozia sudetica perianth.
terminal branch - 
branch developed directly from apical cell divisions, usually replacing one half of a leaf. Example: Frullania californica
thallose - 
a liverwort with a flat, ribbon-like growth form; contrasted with leafy. The ribbon may be largely unbranched or it may bifurcate repeatedly. When the distance between bifurcations is short, rosettes are formed. A thalloid liverwort may have lobed wings that mimic leafy liverworts. (see leafy) All hornworts are thalloid, some liverworts are thalloid, while no mosses are thalloid. Example: Pellia neesianaNote: thalloid refers to a taxon, thallose to a plant form. A thalloid liverwort has a thallose gametophyte. The terms are often mixed up in everyday use.
transverse -
attached at right angles to the stem; a leaf with transversely inserted leaves is at the midpoint between succubous and incubous
trigone - 
the corner of a cell; where three or more cells come together; if the the cell walls are thickened at the corners so the thickenings protrude into the cell space they are called bulging trigones
tufted - 
in liverworts used to describe clumps of rhizoids, growing in tufts from the base of underleaves. Example = Calypogeia fissa
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underleaf -
one of the reduced leaves on the ventral (underside) of an anisophyllous liverwort; common in leafy liverworts with a prostrate rather than ascending growth form. The other two rows of leaves are called lateral leaves. A more technical term for underleaf, used mainly in older references, is amphigastrium; plural=amphigastria. Examples: Left, Gyrothyra underwoodiana; Right, Chiloscyphus coadunatus.
uniseriate - 
cells lined up in a single row; most cilia are uniseriate. Example: Left, Ptilidium californicum; Right, Blepharostoma trichophyllum
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valve - 
one of the four parts of a liverwort capsule wall, or the two outer parts of a hornwort sporophyte. Example: dry capsule of Porella navicularis.
ventral -
the bottom or underside of a liverwort shoot or thallus. Example: left, Scapania bolanderi; right, Preissia quadrata.
ventricose - 
with a pouch like outpocketing, as the male bract of most leafy liverworts. Example: Radula complanata.
verrucose - 
warty bumps, usually referring to ornamentation of spores or cuticle on leaf surfaces. Example: Lophozia gilmanii cell surface.
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