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Section B. General Characters and Character States:
[A. Location or Environmental Position] [B. Position] [C. Arrangement] [D. Orientation] [E. Transverse Posture] [F. Longitudinal Posture] [G. General Structural Position] [H. Embryonic Position]
I. Position and Arrangement
A. Location or Environmental Position
(Classification based on position of organs or parts in their surrounding environment)
- Aerial or Epigeous. Above the ground or water; in the air.
- Emergent. With part(s) of plant aerial and part(s) submersed; rising out of the water above the surface.
- Epipetric. Upon rock.
- Epiphytic. Upon another plant.
- Floating. Upon the surface of the water.
- Submersed. Beneath the surface of the water.
- Subterranean or Hypogeous. Below the surface of the ground.
- Surficial or Epigeous. Upon or spread over the surface of the ground.
(Selected location terms. See habitat prefixes in Chapter 15 and word stems for plant organs and parts in Chapter 4 for meanings of other location terms.)
- Aerocaulous. With aerial stems.
- Aerophyllous. With aerial leaves.
- Amphicarpous. With fruits in two environments; e.g., aerial and subterranean.
- Emersifolious. With emergent leaves.
- Epirhizous. With roots upon another plant.
- Flotophyllous. With floating leaves.
- Geoflorous. With subterranean flowers.
- Petrorhizous. With roots on rock.
- Submersicaulous. With submersed stems.
- Surcarpous. With fruits on surface of ground.
(Classification based on location of parts or organs with respect to other dissimilar parts, or organs)
- Apical or Terminal. At the top, tip, or end of a structure.
- Basal or Radical. At the bottom or base of a structure.
- Continuous. Basal, lateral, and terminal.
- Discontinuous. Basal and lateral, basal and terminal, or lateral and terminal; not continuous.
- Lateral or Axillary. On the side of a structure or at the nodes of the axis.
(Classification based on positional terms usually applicable to individual parts)
a. Androecial Position
(See Perianth and Stamen Position, h. and k.)
b. Branch Position
- Acrocaulous. With terminal branches.
- Basicaulous. With basal branches.
- Caulous. With branches more or less evenly spaced along trunk.
- Subacrocaulous. With branches at or near tip of main stem.
- Subbasicaulous. With branches at or near base of main stem.
- Zonocaulous. With branches intermittently spaced along main stem.
- Accumbent or Pleurorhizal. Reclinate with cotyledon edges against hypocotyl.
- Incumbent or Notorhizal. Reclinate with sides of cotyledons against hypocotyl.
d. Flower, Fruit, Inflorescence, Infructescence Position
- Acrocaulous. At the tip of the stem.
- Amphiflorous, Amphicarpous. Flowers or fruits above and below ground, as in Amphicarpum.
- Axillary. In axil of leaf.
- Basicaulous. Near base of stem.
- Cauline or Caulous. On old woody stem.
- Epiphyllous. From a phylloclad or peculiar bract, as in Tilia.
- Geoflorous, Geocarpous. Flowers or fruits below ground, as in Amphicarpum.
- Infrafoliar. On the stem below the leaves, as in the Arecaceae.
- Interfoliar. On the stem between the leaves, as in the Arecaceae.
- Leaf-opposed. On stem opposite the base of the leaf, as in Alchemilla.
- Suprafoliar. On the stem above the leaves, as in the Arecaceae.
- Terminal. At or near tip of branch.
e. Leaf Position
- Acroramous. Leaves terminal, near apex of branch.
- Aphyllopodic. Without blade-bearing leaves at base of plant.
- Basiramous. Leaves on lower part of branch.
- Cauline or Ramous. Leaves more or less evenly distributed on stem or branch.
- Phyllopodic. With blade-bearing leaves at base of plant.
- Radical. Leaves basal, near ground, usually from caudex or rootstock.
f. Ovary Position
- Inferior. Other floral organs attached above ovary with hypanthium adnate to ovary.
- Half-inferior. Other floral organs attached around ovary with hypanthium adnate to lower half of ovary.
- Superior. Other floral organs attached below ovary.
(Based on position of ovule in locule and orientation of the micropyle and raphe--adapted from Epitropous, dorsal. Ovule pendulous or hanging, micropyle above, raphe dorsal (away from ventral bundle).
Epitropous, ventral. Ovule pendulous or hanging, micropyle above, raphe ventral (toward ventral bundle).
Heterotropous. Ovule position not fixed in ovary.
Hypotropous, dorsal. Ovule erect, micropyle below, raphe dorsal (away from ventral bundle).
Hypotropous, ventral. Ovule erect, micropyle below, raphe ventral (toward ventral bundle).
Pleurotropous, dorsal. Ovule horizontal, micropyle toward ventral bundle, raphe above.
Pleurotropous, ventral. Ovule horizontal, micropyle toward ventral bundle. raphe below.
h. Perianth and Androecium Position (Figure 11-1)
(Classification based on insertion of Floral Parts--Corolla, Calyx, and Androecium--the androperianth)
- Epigyny. The condition in which the sepals, petals, stamens are attached to the floral tube above the ovary with the ovary adnate to the tube or hypanthium.
- Epihyperigyny. The condition in which the sepals, petals, stamens are attached to the floral tube or hypanthium surrounding the ovary; a combination perigyny and partly inferior ovary.
- Epihypogyny. The condition in which the sepals, petals, stamens are attached about half-way from the base of the ovary to the partly adnate hypanthium tube; half-inferior insertion of parts.
- Epiperigyny. The condition in which the sepals, petals, stamens are attached to the floral or hypanthium cup above the ovary with the lower part of the hypanthium completely adnate to the ovary.
- Hypanepigyny. The condition in which the sepals, petals, stamens are attached to the elongate floral tube or hypanthium above the inferior ovary, as in Oenothera.
- Hypogyny. The condition in which the sepals, petals, stamens are attached below the ovary.
- Perigyny. The condition in which the sepals, petals, stamens are attached to the floral tube or hypanthium surrounding the ovary with the tube or hypanthium free from the ovary.
i. Placenta Position (Placentation) (Figure 6-11-2)
- Axile. With the placentae along the central axis in a compound ovary with septa.
- Basal. With the placenta at the base of the ovary.
- Free-central. With the placenta along the central axis in a compound ovary without septa.
- Laminate. With the placenta over the inner surface of the ovary wall.
- Marginal or Ventral. With the placenta along the margin of the simple ovary.
- Parietal. With the placentae on the wall or intruding partitions of a unilocular compound ovary.
- Pendulous, Apical, or Suspended. With the placenta at the top of the ovary.
j. Radicle Position
- Antitropous. With radicle pointing away from hilum.
- Syntropous. With radicle pointing toward hilum.
- Allagostemonous. Having stamens attached to petal and torus alternately.
- Antipetalous. Opposite the petals.
- Antisepalous. Opposite the sepals.
- Cryptantherous. With stamens included.
- Diplostemonous. With stamens in two whorls, outer opposite the sepals, inner opposite petals.
- Epipetalous. With stamens attached to or inserted upon petals or corolla.
- Episepalous. With stamens attached or inserted upon sepals or calyx.
- Obdiplostemonous. With stamens in two whorls, outer opposite petals, inner opposite the sepals.
- Phanerantherous. With stamens exserted.
l. Style Position
- Gynobasic. At the base of an invaginated ovary.
- Lateral. At the side of an ovary.
- Subapical. At one side near apex of ovary.
- Terminal or Apical. At the apex of the ovary.
(Classification based on location of organs or parts in relation to each other)
- Alternate. One leaf or other structure per node.
- Clustered, Conglomerate, Agglomerate, Crowded, Aggregate. Parts dense, usually irregularly overlapping each other.
- Continuous. Symmetry of arrangement even, not broken.
- Decussate. Opposite leaves at right angle to preceding pair.
- Distichous. Leaves 2-ranked, in one plane.
- Equitant. Leaves 2-ranked with overlapping bases, usually sharply folded along midrib.
- Fasciculate. Leaves or other structures in a cluster from a common point.
- Geminate or Binate. Paired; in pairs.
- Imbricate. Leaves or other structures overlapping.
- Interrupted or Discontinuous. Symmetry of arrangement broken, with uneven lengths of internodes.
- Loose, Distant, or Scattered. Parts widely separated from one another, usually irregularly.
- Opposite. Two leaves or other structures per node, on opposite sides of stem or central axis.
- Polystichous. Leaves or other structures in many rows.
- Rosulate. Leaves in a rosette.
- Secund or Unilateral. Flowers or other structures on one side of axis.
- Tetrastichous. Leaves or other structures in four rows.
- Tristichous. Leaves or other structures in three rows.
- Whorled, Radiate, or Verticillate. Three or more leaves or other structures per node.
(Classification based on arrangement with special terms applicable to individual plant parts)
a. Stamen Arrangement (Figure 6-7-2)
(See General Arrangement for additional terms)
- Didymous. With stamens in two equal pairs.
- Didynamous. With stamens in two unequal pairs.
- Tetradynamous. With stamens in two groups, usually four long and two short.
- Tridynamous. With stamens in two equal groups of three.
b. Thecal Arrangement (Figure 6-7-3)
(The thecae in this classification can be conjunctive or disjunctive.)
- Divergent. Thecae or anther cells divaricate or separated from one another at an acute angle to the connective or filament.
- Oblique. Thecae or anther cells lower on one side of connective than the other.
- Parallel. Thecae or anther cells along side of the connective or longitudinal to each other.
- Transverse or Explanate. Thecae or anther cells with maximum divergence of about 90( from the connective or filament.
(Classification based on arrangement of parts in relation to vertical angle of divergence from a central axis or point)
- Acroscopic. Facing apically.
- Agglomerate, Conglomerate, Crowded, or Aggregate. Dense structures with varied angles of divergence.
- Antrorse. Bent or directed upward.
- Assurgent. Directed upward or forward.
- Basiscopic. Facing basally.
- Connivent. Convergent apically without fusion.
- Contorted. Twisted around a central axis; twisted.
- Declinate. Directed or curved downward.
- Deflexed. Bent abruptly downward.
- Dextrorse. Rising helically from right to left, a characteristic of twining stems.
- Inflexed. Bent abruptly inward or upward.
- Patent. Spreading.
- Pendulous. Hanging loosely or freely.
- Reclinate. Bent down upon the axis, no angle of divergence.
- Reflexed. Bent or turned downward.
- Retrorse. Bent or directed downward.
- Salient, Porrect, or Projected. Pointed outward, usually said of teeth.
- Sinistrorse. Rising helically from left to right, a characteristic of twining stems.
- Twining. Twisted around a central axis.
(Classification based on stated degrees of divergence)
- Appressed or adpressed. Pressed closely to axis upward with angle of divergence 15° or less.
- Ascending. Directed upward with an angle of divergence of 16-45°.
- Depressed. Pressed closely to axis downward with angle of divergence of 166-180°.
- Descending. Directed downward with an angle of divergence of 136-165°.
- Divergent, Patent, or Divaricate. More or less horizontally spreading with angle of
divergence of 15° or less up or down from the horizontal.
- Horizontally. Spreading outward at 90° from vertical axis or plane.
- Inclined. Ascending at 46-75° angle of divergence
- Reclined. Descending at 106-135° angle of divergence.
- Resupinate. Inverted or twisted 180°, as in pedicels in the Orchidaceae.
E. Transverse Posture (Figure 6-11-3)
(Classification based on position of ends of single structure in relation to its center or transverse axis)
- Applanate or Plane. Flat, without vertical curves or bends.
- Arcuate. Curved like a crescent, can be downward or upward.
- Cernuous. Drooping.
- Flexuous. With a series of long or open vertical curves at right angles to the central axis.
- Geniculate. Abruptly bent vertically, usually near the base.
- Incurved. Curved inward or upward.
- Lorate. With elongate vertical waves in the margins or sides at right angles to the longitudinal axis.
- Recurved. Curved outward or downward.
- Squarrose. Usually sharply curved downward or outward in the apical region, as the bracts of some species of Aster.
- Undulate. With a series of vertical curves at right angles to the central axis.
F. Longitudinal Posture (Figure 6-11-4)
(Classification based on position of the sides of a single structure in relation to its central axis)
- Conduplicate. Longitudinally folded upward or downward along the central axis so that ventral and/or dorsal sides face each other.
- Geniculate. Abruptly bent horizontally, usually in series.
- Induplicate. Having margins bent inward and touching margin of each adjacent structure.
- Involute. Margins or outer portion of sides rolled inward over upper or ventral surface.
- Plicate. With a series of longitudinal folds; plaited.
- Revolute. Margins or outer portion of sides rolled outward or downward over lower or dorsal surface.
- Rolled. Sides enrolled, usually loosely, over upper or lower surfaces.
- Sinuate. Long horizontal curves in the body of the structure parallel to the central axis.
- Straight. Without a curve, bend, or angle.
- Tortuous. Irregularly twisted.
- Valvate. Sides enrolled, adaxially or abaxially so that margins touch.
- Abaxial. Away from the axis; the lower surface of the leaf; dorsal.
- Adaxial. Next to the axis; facing the stem; ventral.
- Apical. At or near the tip.
- Basal. At or near the bottom.
- Central. In the middle or middle plane of a structure.
- Circumferential. At or near the circumference; surrounding a rounded structure.
- Distal. Away from the point of origin or attachment.
- Dorsal. Pertaining to the surface most distant from the axis; back of an outer face of organ; lower side of leaf; abaxial.
- Marginal. Pertaining to the border or edge.
- Medial. Upon or along the longitudinal axis.
- Peripheral. On the outer surface or edge.
- Proximal. Near the point of origin or attachment.
- Subbasal. Near the base.
- Subterminal. Near the apex.
- Ventral. Pertaining to the surface nearest the axis; inner face of an organ; the upper surface of the leaf; adaxial.
(Selected terms for location on a structure. The meanings of many additional terms can be determined from the positional prefixes and word stems of plant organs and parts in Chapter 4.)
- Acrocaulous. At tip of stem.
- Basipetiolar. At the base of the petiole.
- Centroramous. At the center of the branch.
- Dorsilaminar. On dorsal side of blade.
- Laterospermous. On the side of the seed.
- Pericarpous. Around the fruit.
- Suprarhizous. On top of the root.
- Ventristipular. On ventral side of stipule.
H. Embryonic Position
(Classification based on position and arrangement of immature organs or parts)
1. Aestivation or Prefloration (Figure 6-12-1)
(Classification based on position of embryonic perianth parts. Calyx and corolla may have different aestivation types.)
- Alternate. Having structure in two rows or series so that the inner structure has its margins overlapped by a margin from each adjacent outer structure.
- Cochleate. Having one hollow or helmet-shaped structure which encloses or covers the others.
- Contorted. Having several struc tures in a whorl or close spiral with one margin covering the margin of an adjacent structure.
- Convolute. Having one leaf or perianth part rolled in another, usually twisted apically.
- Imbricate. Having margins overlapping.
- Induplicate. Having margins bent inward and touching margin of adjacent structure.
- Quincuncial. Having five structures, two of which are exterior, two interior, and a fifth with one margin covering interior structure and other margin covered by that of one of the exterior structures.
- Valvate. Having margins of adjacent structures touching at edges only.
- Vexillate. Having one structure larger than others which is folded over smaller enclosed structures.
2. Cotyledon Ptyxis (Figure 6-12-2)
(Classification based on position of cotyledons in seed)
- Conduplicate. Cotyledons folded lengthwise along midrib with one cotyledon covering other and inner cotyledon covering hypocotyl.
- Contortuplicate. With weirdly folded corrugate cotyledons.
- Diplecolobal. With incumbent cotyledons folded two or more times.
- Spirolobal. With incumbent cotyledons folded once.
3. Ptyxis (Figure 6-12-2)
(Classification based on rolling or folding of individual embryonic leaves and arrangement of embryonic leaves within a structure; vernation according to most authors). Adapted from Davis and Heywood (1963).
- Circinate. With lamina rolled from apex to base with apex in center of coil.
- Conduplicate. With lamina folded once adaxially along midrib or midvein.
- Convolute. With one lamina enrolled in another lamina.
- Corrugate. With lamina irregularly folded in all directions, wrinkled.
- Curvative or arcuate. With lamina folded transversely into an arc.
- Implicate. With both lamina margins folded sharply inward.
- Inclinate. With lamina folded or curved transversely near the apex.
- Involute. With lamina margins enrolled adaxially.
- Planate or Plain. With lamina flat, without folds or rolls.
- Plicate. With many longitudinal folds in lamina.
- Reclinate. With lamina folded or curved backwards from near its base so that embryonic blade is parallel to its petiole, hypocotyl, or stem.
- Replicate. With lamina folded once abaxially along midrib or midvein.
- Revolute. With lamina margins enrolled abaxially.
- Supervolute. With lamina with one edge tightly enrolled and with the other loosely enrolled covering the first, loosely convolute.
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