Glossary of Plant Terms

 

N to Q

N

narrow-elliptic: broadest about the middle and with margins symmetrically curved, and with a ratio of less than 3:2. 

native: naturally occurring in the area, but not necessarily confined to it. cf. endemic.

naturalized: originating elsewhere but established and reproducing itself as though native of the area.

net veins: forming a network or reticulum; e.g. of veins. 

node: the level of a stem at which one or more leaves arise. cf. internode.

non-vascular plants: plants without vascular tissue (mosses, liverworts and hornworts). cf. vascular plants.

nut: a dry indehiscent one-seeded fruit formed from two or more carpels.

nutlet: A small nut; often incorrectly applied to the units of the fruit produced in families such as Lamiaceae and Verbenaceae.

O

ob-: a prefix; the other way around, as in obovate, the reverse of ovate.

obcordate: heart-shaped and attached at the narrow end. cf. cordate.

oblanceolate: reverse lanceolate, broadest in the upper third and 3 to 6 times as long as broad. cf. lanceolate.

oblique: asymmetric, of a leaf, leaf base or other organ, having the sides unequal.

oblong: ± rectangular shape, with length much greater than the breadth.

obovate: 2-dimensional shape, reverse ovate, broadest above the middle with the length 1 to 3 times the breadth.

obovoid: a solid or 3-dimensional shape, reverse ovoid, but broadest above the middle and with length 1 to 3 times as long as broad. cf. ovoid.

obpyriform: pear-shaped, with the point of attachment at the broader end, similar to ovoid. cf. pyriform.

obsolete: reduced to a rudiment, or completely lacking, as in the ovary in male flowers. cf. rudimentary, vestigial.

obtriangular: a 2-dimensional shape, 3-angled and 3-sided and attached at the narrower end. cf. triangular.

obtuse: blunt or broadly rounded, e.g. of a lamina apex, or of a lamina base.

ocrea: ochrea; a sheath formed from two fused stipules encircling the node, as in as in the ocrea of Acetosa sagittata. pl. ocreae.

odd-pinnate: imparipinnate, unevenly pinnate, a pinnate leaf with a single terminal leaflet, usually with an odd number of leaflets. cf. paripinnate.

oil dots: see oil glands

oil glands: oil dots; small structures embedded in the tissue of a leaf or other organ and secreting a volatile oil, mostly visible as small translucent dots against a strong light (hand lens usually needed). The leaf or other organ aromatic when crushed. Usually distinct in certain families, such as Myrtaceae and Rutaceae.

one-foliolate: 1-foliolate, unifoliolate; of a leaf, a compound leaf reduced to a single leaflet, usually recognized by the joint or articulation near the apex of the petiole. In this key 1-foliolate leaves are included in ‘simple’ leaves, as often they are difficult to distinguish.

one-veined: describing an organism, such as a leaf, with only the midvein visible.

open communities: a community dominated by trees or shrubs with relatively narrow isobilateral leaves forming sparsely foliaged crowns; the canopy, if present, is sparse and often not continuous, allowing sunlight to reach the ground within the community. cf. open forest.

open forest: a non-rainforest community dominated by trees with relatively narrow isobilateral leaves forming sparsely foliaged crowns (usually species of eucalypts); the forest canopy is sparse and often not continuous, allowing sunlight to reach the ground within the forest. cf. closed forest.

operculum: see calyptra.

opposite: inserted at the same level, as in leaves on the opposite side of the stem. cf. alternatesub-oppositewhorled and pseudo-whorled.

orbicular: see globose.

organ: any definite part of a plant structure, e.g. a leaf, flower etc.

orifice: a small opening or aperture, as at the apex of figs, the inflorescence and fruit of species of Ficus.

orthographic variant: (in botanical nomenclature) an unintentional misspelling of the scientific name in the original description of the taxon, as in the spelling of Cryptocarya meissneriana for Cryptocarya meisneriana.

ostiole: an opening or a pore, e.g. at the apex of  figs, the inflorescence and fruit of species of Ficus.

outlier: a population that is outside the normal or continuous range of a taxon, as in Ozothamnus rufescens.

ovary: the basal portion of a carpel or a group of fused carpels in which one or more ovules are enclosed, and which after fertilization develops into the fruit. The ovary can be superior or inferior or half inferior, depending on the level at which the floral parts are inserted.

ovate: egg-shaped, a 2-dimensional shape and broadest below the middle, with the length 1 to 3 times the breadth, e.g. of a leaf.

ovoid: egg-shaped, a solid or 3-dimensional shape with length 1 to 3 times the breadth, as in a fruit.

ovule: a structure in seed plants which after fertilization develops into the seed, and in flowering plants formed within the ovary.

P

palmate: digitate; (1) of a leaf, a compound leaf with 3 or more leaflets arising from the one point at the top of the petiole; (2) of veins in a lamina, radiating from the one point. adv. palmately.

palmately trifoliolate: of a leaf, a compound leaf with 3 leaflets arranged palmately, i.e. all the petiolules of about the same length, and the central one without a joint at or near the apex. cf. pinnately trifoliolate.

palmatifid: of a leaf cut into lobes to less than halfway and in a palmate form. 

palmatisect: of a leaf cut into lobes to more than halfway and in a palmate form.

panicle: determinate, compound inflorescence with a main axis and lateral branches which are further branched, and in which each axis ends in a flower or flower bud. adj. paniculate.

papillae: small elongated or nipple-shaped outgrowths on an organ.

papillose: covered with papillae.

pappus: a series of hairs or scales above the inferior ovary and outside of the corolla, persisting on the fruit and assisting in its dispersal, as in many Asteraceae; possibly a modified calyx.

parallel venation: a form of longitudinal venation with several major veins, usually closely spaced and ± equally distant from one another, and the margins of the organ usually ± parallel, as in grass leaves. cf. longitudinal venation.

parasite: an organism growing and feeding upon another organism (the host). cf. saprophyte.

paripinnate: evenly pinnate, a pinnately compound leaf without a true terminal leaflet and therefore usually with an even number of leaflets. cf. imparipinnate.

pedate: a palmately compound leaf with the lateral leaflets divided again. cf. ternate.

pedicel: the stalk of a flower.

pedicellate: with a pedicel.

peduncle: (1) the stalk of an inflorescence; (2) the stalk of a solitary flower when that flower represents a reduced inflorescence.

pedunculate: with a peduncle.

pellucid: translucent, transparent, e.g. of oil dots in leaves.

peltate: an organ with a stalk or point of attachment on its lower surface away from the margin, often umbrella-like; e.g. of leaves; or of circular scales (peltate scales).

pendent: pendulous; drooping, hanging downwards, e.g. of leaves or branchlets.

penniveined: pinnately veined, veins arranged in a leaf or other organ so that the lateral or secondary veins are conspicuous and often numerous and are more or less parallel to each other, as in a feather. cf. palmately veined, longitudinally veined.

pentamerous: 5-merous; of a flower, having the floral parts, especially the sepals and petals or tepals and usually the stamens, in whorls of 5 or multiples of 5. As in many members of the families Apocynaceae and Fabaceae, e.g. Derris involuta.

perennial: a plant whose life-span extends over more than one growing season.

perianth: the calyx and corolla collectively; especially when they are similar, in which case the individual segments are called tepals, as in Geitonoplesium cymosum, or if there is only one whorl and it is difficult to ascertain if it is the calyx or corolla, as in Brachychiton acerifolius.

pericarp: the wall of the fruit, developed from the ovary wall. cf. endocarpepicarpexocarpmesocarp.

perigynous: of the floral parts (sepals, petals and stamens), when they are inserted on an expanded receptacle (hypanthium), the hypanthium can be saucer-shaped, cup-shaped to cylindrical. cf. epigynoushypogynous.

persistent: remaining attached, e.g. of floral parts remaining until the fruit is mature; of a leaf base; remaining attached to the plant after the leaf or frond has been shed, as in treeferns.

petal: segment of the corolla, the structures surrounding the fertile organs of the flower, usually free and coloured; inside the sepals. cf. corollasepalcalyx.

petaloid: resembling a petal, especially in colour and structure, as in the sepals in Aphanopetalum, sepals and stamens in species of Commersonia and staminodes in Eupomatia species.

petiolar glands: glands on the  petiole, may be sessile or stalked, as in Passiflora edulis.

petiole: the stalk of a leaf. adj. petiolate.

petiolule: the stalk of a leaflet. cf. terminal petiolule.

phyllode: a flattened petiole, leaf-like in appearance and function, replacing the lamina, as in many wattles. In the key phyllodes are included in ‘simple’ leaves. cf. simple leaf.

phylogeny: the evolutionary development of a plant group, i.e. its derivation from its ancestors and the relationship among its members. adj. phylogenetic.

pilose: hairy with long soft weak hairs which are clearly separated but not sparse.

pinna: a leaflet, a primary segment of the lamina of a compound leaf. pl. pinnae.

pinnate: (1) (1-pinnate) of a leaf, with the lamina divided into pinnae in 2 rows along a rachis, once compound, cf. imparipinnateparipinnate, bipinnate, tripinnate; (2) of veins, with the secondary veins arranged regularly, cf. penniveined.

pinnately trifoliolate: of a compound leaf, with 3 leaflets arranged pinnately, i.e. the terminal petiolule usually jointed and longer than the lateral ones. cf. palmately trifoliolate.

pinnatifid: of simple leaves or leaflets, with the lamina cut into shallow lobes on both sides of the midrib. cf. pinnatisect.

pinnatisect: of simple leaves or leaflets, with the lamina cut down almost to the midrib, e.g. as in the ultimate segments of some fern fronds. cf. pinnatifid.

pinnule: leaflet of a bipinnate leaf. pl. pinnules.

pistil: the female part of a flower, a free carpel or a group of fused carpels. cf. gynoecium.

pistillode: a sterile gynoecium, usually rudimentary.

pitted: having numerous small depressions on the surface.

plicate: folded or pleated like a fan, as in the leaves of Livistona australis.

plumose:feather-like, with a central axis and fine hairs arising from it. e.g. the fruiting style of Clematis species, and the pappus of some species in family Asteraceae.

pneumatophores: specialized vertical roots produced by some vascular plants which grow in water, water-logged mud or tidal swamps; the roots contain spongy tissue which enables them to exchange gases with the atmosphere through lenticels in their aerial portions, as in many mangroves.

pod: legume, a dehiscent dry fruit that that usually opens along 2 sutures, or rarely an indehiscent dry fruit (an indehiscent pod), as in species of Austrosteenisia.

polyembryonic: seeds with more than one embryo within each seed, as in Syzygium paniculatum.

pome: a fleshy false fruit formed from an inferior ovary in which the receptacle or hypanthium has enlarged to enclose the ripened ovary, as in Rhaphiolepis.

prickle: a hard, pointed outgrowth from the surface of a plant, involving several layers of cells, but not containing a vascular system. adj. prickly. cf. spinebristlethorn.

processes: outgrowths or projections from a surface, e.g. papillae.

procumbent: having stems trailing or spreading over the ground.

prop roots: stilt roots; roots growing down to the soil from the lower stem or branches, as in mangroves and some palms, e.g., Archontophoenix cunninghamiana.

prostrate: lying flat on the ground.

pruinose: of a surface, having a whitish, waxy, powdery bloom that can be rubbed off, as on many purplish or black fruit. cf. glaucous.

pseudo-: a prefix, false.

pseudo-pinnate: a lateral shoot resembling a pinnate leaf, i.e. a shoot with limited growth and with simple leaves arranged in 2 rows like the leaflets of a pinnate leaf.

pseudo-whorled: of leaves, arranged in clusters on the stem, the clusters separated by regular intervals, usually produced behind a scaly resting bud. cf. whorledalternateoppositesub-opposite.

pubescent: covered with short, soft hairs. 

pulvinule: the pulvinus at the base of a petiolule.

pulvinus: the swelling at the base of the petiole, often capable of changing form to bring about movement of a leaf, sometimes glandular or responsive to touch. Present in simple leaves and compound leaves. A similar swelling near the apex of a petiole is referred to as an upper pulvinus. pl. pulvini.

punctate: gland-dotted, marked with dots.

pungent: (1) ending in a stiff, sharp point, as in spinose teeth; (2) having an acrid taste or smell.

pustule: a blister or pimple, generally referring to the bark surface, usually formed from lenticels.

pyrene: the ‘stone’, i.e. endocarp and seed of a drupe. Usually used in the case of fruit in which the endocarp is cartilaginous or bony.

pyriform: a 3-dimensional shape, pear-shaped, with the point of attachment at the narrow end, similar to obovoid.

Q

quadriternate: 4-ternate; four times ternate, the pinnules of a triternate leaf are each divided further into leaflets or segments, as in Clematis leptophylla.

quandong: the rough surface or sculptured stone (endocarp), as in the fruit of species of Elaeocarpus.

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