Plant Terminology

Parts of a Flower Pedicel--the stalk of an individual flower Calyx--outermost whorl of a flower Sepal--one member of the calyx Corolla--second whorl of a flower Petal--one member of the corolla Polypetalous--petals are free Sympetalous--petals are fused together Perianth--the calyx and corolla together Androecium--whorl of male sex parts Stamen--one member of the androecium Filament--stalk Anther--terminal sac where pollen is produced Gynoecium--whorl of female sex parts Apocarpous-gynoecium of many separate carpels; the flower has many simple pistils Syncarpous-gynoecium of many fused carpels; the flower has a compound pistil Unicarpellate-gynoecium with only one carpel; the flower has a simple pistil Carpel--one member of the whorl of gynoecium Ovary--at base of carpel, contains one or more ovules Ovule--develops into seed if fertilized Locule/cell--open space within ovary Septa--dividing walls Stigma--sticky tip of carpel that receives pollen Style--connects ovary to stigma Hypanthium--saucer-shaped, cup-shaped, or tubular expansion of the floral axis that produces sepals, petals and stamens from its upper margin Complete--flower has all four whorls Incomplete--flower lacks one or more whorls

Floral Symmetry

Actinomorphic/regular/radially symmetrical--the flower has many axes of symmetry Zygomorphic/irregular/bilaterally symmetrical--the flower has only one line of symmetry

Reproductive Variations Bisexual/perfect/monoclinous/synoecious--has functional androecium and gynoecium Unisexual/imperfect/diclinous--either functionally male or functionally female Staminate--flower only has functional stamens Carpellate--flower only has functional carpels Monoecious--staminate and carpellate flowers on the same plant Dioecious--staminate and carpellate flowers on separate plants

Inflorescence Types

Inflorescence--distribution flowers Peduncle--stalk of inflorescence Pedicel--stalk of individual flower Bract--small leaf at base of flower or inflorescence Involcure--cluster of bracts

Solitary--just one flower on the peduncle Spike--one unbranched axis and the flowers sessile (without pedicels) Raceme--one unbranched axis and the flowers with pedicels Panicle--the main axis has branches that are in turn rebranched

Corymb--pedicels elongate to same level, youngest flower in center Cyme--pedicels elongate to same level, oldest flower in center Umbel--all the pedicels arise from one point at the top of the peduncle

Compound umbel--peduncles arise from one point and each in turn bears a smaller umbel Capitulum/Head--rounded or flat-topped cluster of sessile flowers Catkin--spike or raceme of unisexual flowers without petals that falls as a whole Spadix--spike with thickened, fleshy axis enveloped by conspicuous or colored bract called a spathe; flowers are often minute and frequently unisexual

Fruit Types Categorized by whether they are dry or fleshy and whether they dehisce (split open) at maturity

Dry, Indehiscent

Achene--one seed that is free of the pericarp (fruit wall) Samara--an achene with a wing for wind dispersal Nut--one seeded by abortion (only one ovule matures), usually hard-shelled. A small nut is a nutlet Caryopsis/Grain--one seed that has the seed coat fused to the pericarp

Dry, Dehiscent

Follicle--from a simple pistil, dehisces along one suture Legume--from a simple pistil, dehisces along two sutures Capsule--usually from a compound pistil, many-seeded Loculicidal--dehisces along the back of each carpel between the septa Septicidal--dehisces through the septa between the carpels Poricidal--opens by holes like a saltshaker

Circumscissile--dehisces in a line around the top, top falls away in 1 piece Schizocarp--from a compound pistil, splits into mericarps (pieces) that enclose one or more seeds and resemble fruits themselves Silicle--short and fat capsule where two halves fall away from central false septum (replum) where seeds are attached Silique--like a silicle except capsule is long and thin Fleshy

Berry--from a compound pistil, few to many seeds Drupe--from a simple pistil, one seed within a stony endocarp Pome--swollen and juicy hypanthium surrounds mature ovary

Other Fruit Terminology Aggregate--fruit composed of mature ovaries from separate pistils of ONE flower Multiple--fruit composed of mature ovaries from separate pistils from SEVERAL flowers Accessory--fruit where the "fruit" part is derived from something other than ovary tissue

Placentation Types

Marginal--ovules arranged along the suture of a single, simple pistil Axile--a separate locule for each carpel and the ovules attached to placentae in the middle where the septa come together Parietal--ovules attached to the wall of a unilocular ovary Free-central--ovules attached to a stalk that arises from the ovary floor but does not reach the roof Apical--ovules attached to the roof of the ovary Basal--ovules attached to the floor of the ovary

Ovary Position Hypogynous--having the stamens, petals, and sepals attached near the base of the ovary and free from it Perigynous--having a hypanthium arising from the base of the floral axis Superior--stamens, petals, and sepals attached below the ovary (hypogynous and perigynous) Semi-inferior/Half-inferior--stamens, petals, and sepals attached alongside the ovary Epigynous/Inferior--stamens, petals, and sepals attached above the ovary

Leaf Terminology

Lamina/Blade--the expanded portion of the leaf Simple--a leaf with a single blade Compound--a leaf with more than one blade Leaflet--blades of a compound leaf Rachis--elongated axis of a compound leaf Palmate--leaflets arranged like spokes of a wheel; lacks a rachis Pinnate--leaflets arranged on either side of the rachis Petiole--the leaf stalk Stipule--a pair of appendages at the base of the petiole

Alternate--leaves are arranged 1 leaf at a node Opposite--leaves are paired on the stem, 2 at each node Whorled--3 or more leaves at a node

Venation--system of principal veins in the leaf blade Palmate--veins are arranged in a radial pattern like fingers from a palm Parallel--veins are arranged in parallel Pinnate--veins branch out from central vein

Vascular tissue (Figure from Bold et al. (1987))

Protostele—simplest, most ancient 1. Solid cylinder of vascular tissue 2. Phloem may surround xylem or is interspersed within (A, A’, A’’) 3. Found in roots of most vascular plants, stems of seedless vascular plant

Siphonostele 1. Central pith (ground tissue) surrounded by vascular tissue 2. Phloem may be only outside, or on both sides of xylem (B’, B’’) 3. Found in stems of seedless vascular stems a. In ferns, leaf gaps form where leaves depart from stem (leaf traces)

Eustele 1. Discrete bundles of vascular tissue surrounding a pith a. Monocot stems dispersed through pith—variation on eustele 2. Found in stems of seed plants

Leaves 1. Microphyll—single strand of vascular tissue, usually small a. Usually derived from protostele b. Characteristic of lycophytes 2. Megaphyll—branching vascular tissue, larger a. Usually siphonostele or eustele