Glossary by Dr. Donald Spoon, with annotations by Dr. Spoon.
List of terms: Click on term for definition.
---- Alelle. A distinct form of a gene producing a specific trait.
An example is the anthocyanin flower patterns (dominant no pattern, recessives plicata, luminata, and glaciata) at the plicata locus. In tetraploid bearded irises there may be only four different alleles on the four homologous chromosomes at the same gene locus, such as the plicata locus. Dominant alleles (Pl for no plicata pattern) require only one allele or dose (Pl,pl,pl,pl,) of the four doses to be expressed. Sometimes, each additional dominant dose makes the trait more or less prominent by a dosage effect as with the dominant inhibitor (Is) of anthocyanin only in the standards. The recessive alleles usually require four doses (pl,pl,pl,pl) to be expressed unless the other alleles are recessives, than there can be a peck order or an overlapping expression of the recessive alleles. Some dominant alleles at the same locus are codominant producing a mixing inheritance with a trait intermediate between the two dominant traits. Likewise, some recessive alleles at the same locus are corecessive with the traits overlapping equally or unequally creating an intermediate trait. The colloquial term for allele is factor.
---- Allopolyploid . Triploid, tetraploid, or octaploid hybrid having sets of chromosomes with nonhomologous structure from different species.
In the autopolyploid all sets of chromosomes have similar, homologous chromosomes.
---- Alternation of Generation . In plants where the spore forming sporophyte repeatedly follows the gamete producing gametophyte.
With combination the reduced chromosomal numbered male and female gametes redouble the chromosome number to produce the zygote. The zygote develops into the embryo that develops into the new sporophyte plant that by meiosis (reduction and division) produces microgametophytes that produce the male gametes and macrogametophytes that produce the female gametes.
---- Amphidiploid . Hybrid from two tetraploid species each contributing two sets of chromosomes in their gametes for a total of four sets in the zygote. The two diploid sets are so different morphologically that they do not independently assort at meiosis, thus the tetraploid hybrid behaves more like a diploid.
---- Aneuploid . Hybrid that lacks or adds one or more chromosomes in the sets of chromosomes.
The result is a chromosome number less or more than the multiple of sets would dictate. The mismatches at meiosis when the homologous chromosomes line up and synapse may make the hybrid sterile.
---- Arilbred, AB. An iris cultivar that is at least 1/8th aril (oncocylous or regalia bearded irises) crossed with other bearded irises.
---- Amoena. (ah me nut) White standards and colored falls.
It is difficult to give an operational definition of the term amoena, meaning ‘pleasing’. Originally, amoena meant only cultivars with white standards and anthocyanin pigmented falls, and later just colored falls that included pink and yellow amoenas. Possibly, the best modern description is anthocyanin pigment in the falls and none in the standards. In such an amoena, the standards can be white, cream, yellow, pink, peach, red-orange, or orange. Also, in the falls the anthocyanin pigment pattern can overlay any carotenoid pattern. Amoena luminatas have only the fall’s anthocyanin pattern displayed as a luminata color pattern. Amoena plicatas have a plicata color pattern only in the falls. The anthocyanin amoena patterns are produced by two different genes; in one, the pattern is recessive requiring four recessive doses for expression and in the other, the pattern is dominant with dosage effects so that only with four doses (Is Is Is Is) are the standards free of anthocyanin pigment. Complicating the usage of the term, there are patterns also called amoena in the carotenoid pigment colors that require four recessive alleles for the standards to be white. These are named for the falls color, such as yellow amoena, pink amoena, and orange amoena.
---- Anthocyanin pigment . The main water soluble pigment present in the central vacuole of the epidermal cells that give the iris flower their nearly black, violet, blue, light floridor blue, maroon, brick red, brown, tan, and orchid pink coloration.
There are several groups of these water soluble, cell-sap pigments that are lumped together under the term ‘anthocyanin’ that is the major group.
---- Anthers. Male structure bearing two elongate lobes filled with maturating pollen.
When fully developedthe lobes rupture or dehisce releasing the powdery pollen grains. The anther plus its supportive filament is the stamen.
---- Autopolyploid. Hybrid with 4 or 8 sets of chromosomes in which all sets are homologous with similar structures.
Autopolyploids are produced by natural processes or chemical induction.
---- Backcross . Inbreeding when cultivar or species hybrid is crossed as pod or pollen parent on either of its parents.
---- BB. Border bearded irises , 16-27.5” (41-70 cm) tall stalks that bloom with the tall beardeds (TBs) and MTBs.
Border beardeds are mostly from TB breeding. With esthetically pleasing proportion Border Beardeds have larger and wider flowers as well as thicker stalks than the MTBs of similar stalk heights. A seedling with stalks shorter than 27.5” (70 cm) yet TB sized flowers is best used for further hybridizing and not introduced unless it carries unique traits or color of considerable value to other hybridizers. (Ben Hager introduced his excellent parent for modern formed, reliable rebloomers, the very short TB ‘Bonus Mama’)
---- Beard, Bd or Beards, Bds . Elongate group of fuzzy, thin hairs in the middle of the falls, at their bases and extending about a third to a fourth of the length of the falls.
Bearded irises are called pogon and beardless called apogon (a- means without). The Eupogons (true bearded) have bushy beards with multicelllular hairs while pogons like arils have sparse beards with unicellular hairs. Genetically, long, wide beards are dominant to short, narrow beards.
---- Bee pod . Term used to describe a pod pollinated by a bee, bumblebee, or other flying pollinators, such as sphinx moths.
Our experience is that most pods that are not human pollinated are pollinated by crawling insects, and the offspring of these pods indicate that the flower was more likely to be self pollinated than cross pollinated as can be determined by examining the traits of the offspring.
---- Bicolor . Color pattern with standards a different color than the falls as in various dominant and recessive amoenas, inverse amoenas, variegatas, dark tops, etc.
This broadly general, nonspecific term is ambiguous and does not distinguish the type of color pattern or combination. It does not include color patterns with two different colors in the falls or in the petals and beards.
---- Bitone . Color pattern with the falls a darker shade of the color in the standards.
Neglectas are blue-violet or violet bitones with the falls the darker shade. When the shade difference is slightly visible it is accurately called a minimal bitone. Reverse bitones are when the falls are the lighter shade.
---- Blade. Each leaf in the fan of foliage and also the expanded leaf-like part of the flower petals (also called a disc).
The base of the blade where it encloses the rhizome is the sheath. The narrow base of the flower petal is the claw. It is appropriate for the iris, formerly called the sword lily in the middle east, to have its leaves called blades, arranged in a fan of sword blades like in the grand hall of a castle.
---- Blend . Color pattern with obvious combination of two or more, unevenly mixed colors often from opposite sides of the color wheel, such as purple and yellow overlapping to produce areas of maroon.
A blend can have the different colors also appearing separately in certain areas. A self can be a blend of two 3 completely mixed colors, such as yellow and violet giving maroon, but it would not be called a blend color pattern.
---- Border . A recessive trait where the edge of the falls lacks anthocyanin pigment in a broad area around the periphery of the falls.
The border can be white or any of the carotenoid colors or color patterns. Sometimes called a halo or rim when the border is narrow. If the border is very wide it can be called a band or a graded band that is more intensely pigmented on the periphery.
---- Bride’s Halo Border Pattern . A carotenoid pigmented border around both the falls and standards.
The ground inside the border can be white or have an anthocyanin pigment pattern.
---- Bracts . Leaf like blades of unequal lengths arising in pairs from the node at each branch of the stalk.
Bracts can develop by the unequal lengthening of the two spathes inclosing the flower cluster.
---- Calyx . Grouping of the three sepals, called falls in irises.
---- Capsule . Unruptured, dried seed pod developed from the flower ovary.
---- Carotenoids , “Carotins.” Lipid soluble pigments in chloroplasts and chromoplasts including light yellow xanthophylls and deeper yellow carotenes.
The red-orange carotene pigment is called lycopene. The authors have coined the term “Carotins” for all these lipid soluble pigments to be used with “Cyanins” for all water soluble pigments. Both terms are three syllable words with first syllable accents to substitute or to be used as synonyms for the five syllable words Carotenoids and Anthocyanins.
---- Centromere . Area of the chromosome where the spindle fibers attach and where the chromatids are joined before being pulled apart in the anaphase stage of division.
---- Chimera . Variation in a flower part that is passed on to the new increases such as the tendency to have a random darker streak in a petal, a single darker petal, or have one half the flower a different color or white. Also, where different parts of the flower are diploid or tetraploid.
---- Chromatids. Conjoined, replicated condensed daughter chromosomes united at their kinetochores or centromere.
---- Chromoplasts . Membrane bound structures in the cytoplasm of epidermal cells of flowers that contain the lipid soluble carotenoid pigments.
---- Chromosomes . Heredity carrying structures in the cell’s nucleus composed of DNA and associated structural and regulatory proteins.
Antimitotic chemicals like colchicines can disrupt the spindle fibers and leave the undivided chromosomes (called chromatids) stranded at the metaphase stage mitosis. The replicated pairs of chromosomes shorten over a thousand fold with five fold super coiling to form joined pairs of fingerlike structures that are directly visible with contrast enhancing microscopy. The histone proteins of chromosomes stain with basic dyes for permanent slide preparations. Giemsa staining is used to show distinctive chromosome band patterns.
---- Claw . The narrow base of the standard and fall. The claws are more narrow and spatulate in standards
while wider and flatter in the falls.
---- Classic . Any iris cultivar introduced from 11 to 29 years ago, historics are 30 years old or older, and moderns are introduced in the last 10 years.
Many classics are cultivars with modern wide, ruffled form. 4 The tested and proven classics are all inexpensive and offer the best value for iris growers and beginning hybridizers.
---- Climatic Zones . Regions that posses the same minimum winter temperature that present a similar cold stress to iris.
The zones are based on 10 degree F differences divided into an ‘a’ and ‘b’ component of 5 degree F difference with ‘b’ the colder. The combined duration of exposure to cold winter wind and its ability to desiccate and freeze iris blades, roots, and rhizomes can greatly moderate the significance of the assigned climatic zone that are based merely on the lowest temperature on the coldest night.
---- Clump. Rooted, circular group of vegetatively produced, interconnected rhizomes, some with fans of blades and new increases.
When divided into separate iris plants, each is an asexually reproduced, genetically identical clone derived from the sexually produced zygote.
---- Color Wheel . Pie-shaped circle with slices of different colors with the three basic spectrum colors (red, blue, and yellow) across from colors produced by mixing two of them.
Red is across from green, blue across from orange, and yellow across from violet. Mixing complimentary colors from the opposite sides of the color wheel produce darker or grayed tones, or at the extremes of intensity near black. Anthocyanin blue and violet pigment colors are on the opposite side from the carotenoid colors yellow, orange, and red.
---- Corolla . Grouping of the three petals, called standards in irises.
---- Cousin Cross . Cross of two cultivars where each has a parent with the same grandparents.
This is considered by some hybridizers to be a moderate, more acceptable form of inbreeding than sibling crosses, back crosses on parents, or self crosses.
---- Crests . The two, up curved petaloid structures projecting from at the top of each style arm just above the flap of tissue called the stigmatic lip.
The crests help the standards shield the stigmatic lip from rain and wind that could dislodge the attached pollen. The crests often are the only flower part possessing laced edges or in fully laced flower the crests usually exhibit the most pronounced lace.
---- Creped. Petal texture that is randomly indented and raised areas producing an uneven surface.
---- Crimped . Edges of the petals have fine folds, or pleats.
---- Cross Records . Detailed tallying of the pod followed by pollen parent of each cross made that is numbered and properly dated.
Notes of weather conditions, time of day, and goal being advanced are advantageous. Hybridizers are encouraged to make reverse crosses whenever possible. Irises are not neuter, rather each plant is both male and female at the same time and may be fertile in both directions. It is archaic to term these cross records as ‘stud books.’ Crossing irises is not analogous to a stallion mounting a mare, rather it uses pollen that are gametophyte plants. Most early hybridizers were men but now iris hybridizing is performed by men, women, and children. The actual fertilization occurs between the gametes provided by the two gametophytes, the pollen and ovules. The pollen dauber just helps bring the gametophytes together so that the gametes they produce can unite to form zygotes and develop into sporophyte plants.
---- Cultivar . Subset of the general term variety that is a cultivated variety,
usually the product of human hybridization rather than a naturally occurring variety of a species or a natural hybrid of two species. Cultivar names are not Latinized or in italics and are usually enclosed in apostrophe marks. In some publications the cultivar are in bold type to make it easier to single out when scanning the text.
---- “Cyanins” . Newly coined term by the authors that lumps together all those water soluble pigments found in the central vacuole and in membrane bound packaging vesicles on route to the central vacuole.
The predominant “cyan” pigments are the anthocyanin; however, there are many other associated pigments and their attached sugars and metal ions that moderate the color perceived, that includes the pH of the central vacuole. These “cyan” pigments and pigment complexes account for the colors we perceive as black, black-violet, violet, blue-violet, blue, maroon, brown, tan, orchid pink, and brick red.
---- Cytoplasm . Living protoplasm between the outer plasma membrane and inner nuclear envelope membranes that separates the cytoplasm from the nucleoplasm that is enclosed within the nucleus.
---- Dehisce . (deep hiss). When anther lobes open and release the pollen or when the seed pods open and dispense the seeds.
---- Diamond dusted . Tiny, raised and cone-shaped epidermal cell surfaces on the petal surfaces which act as prisms, each creating a spectral rainbow of color, and like tiny diamonds refracting and reflecting sparkles of light. Can be white, silver, or gold.
---- Diploid . Means two sets of chromosomes.
A diploid hybrid, variety, or species has two sets of chromosomes in the growing, flowering sporophyte. A diploid plant has one set of chromosomes in its haploid gametophyte that produces haploid gametes, the egg and sperm nucleus, that unite to form the diploid zygote, embryo, and sporophyte.
---- Distilata. New color pattern where there is an isolated anthocyanin pigmented area with speckling and/or vein streaks positioned distal from the beards and below the middle of the falls.
Also called the ‘line and speckle’ pattern. Some cultivars lack the lines and have only the distal speckle pattern.
---- Division . Iris plant composed of one rhizome, its roots, fan of blades, and laterally developing increases.
The product of dividing up the interconnected iris clump.
---- DNA. Deoxyribonucleic acid , the helical molecule containing like steps in a twisted ladder the pairs of four different hydrogen bonded nucleotide bases that record the triplet code for the amino acid sequences of the cell’s proteins.
In the nucleus the DNA is chromosomal DNA, and in the cytoplasm it is plasmid
DNA in the mitochondria and chloroplasts.
---- Domed. Flower form where the three standards are arched upward and rounded inward to close at the top, as opposed to erect and not closed, or open and arched outward.
---- Dominant allele . Allele that masks the trait of one or more recessive alleles at the same locus in the heterozygous condition.
Here designated with a capital letter (2N: Aa, 4N:Aaaa, AAaa, and AAAa) and the recessive designated as a lower case letter.
---- Emma Cook pattern . Variation of the dominant amoena color pattern (Is or I sub s gene) with the anthocyanin pigmentation only in a distinct, narrow border on the falls and with no anthocyanin pigmentation in the standards.
Cultivars from EMMA COOK pattern breeding can have this anthocyanin pigmented border much broader or grading from darker pigmentation on the edges to lighter in the center of the falls. These variations are most likely due to modifying genes with dosage effects. Pattern named for the cultivar named for his wife by the originator of this pattern, Paul Cook.
---- Endosperm . Part of the seed that surrounds and nourishes the embryo as it germinates and develops into a sporophyte plant with stem, roots, and leaves.
It is a triploid product in diploids or a hexaploid product in tetraploids of the second fertilization when the second sperm nucleus unites with the two polar cells.
---- Eupogon . True bearded iris with a linear beard rather than a diffuse beard as found in the aril irises whose seed has an aril, a cream-white collar surrounding the hilum.
The aril is the remnant of the short rod-like funicle (or funiculum) that attached the ovule to the placenta of the ovary that enlarged into the seed stalk in the seed pod.
In some cultivars the standards are domed yet also overlap at the top of the dome.
---- Enzyme . Protein with reactive site where substrates are brought together or substrates are broken into products in chemical reactions.
The enzyme can catalyze its reaction at rates of millions per second.
---- Epistasis. Where one genotypic locus (the epistatic gene) masks or reduces the expression of the phenotypic trait of one or more other genotypic loci (the hypostatic gene or genes).
A good example is how the dominant (I) locus for anthocyanin inhibition masks the expression of anthocyanin patterns in both standards and falls or the dominant (Is) locus that masks anthocyanin patterns in the standards but not in the falls.
---- Falls, F. Three lower ‘petals’ (botanically falls are the sepals, standards are petals) of the iris flower.
The falls can hang down, curve under, arch, flare, or horizontally flare. Falls possess median, basal beards. The base of the each beard lies between two nectarines. Falls are modified leaves with a narrow, basal claw and broad, distal blade portion that can vary from rounded to elongate. In the falls, chlorophyll producing green cells are present only on the undersurface at their bases.
---- Fan . Group of interlocked, tightly folded blades (leaves) that grow up from the crown of the rhizome where each is unfolded and wrapped around the top half of the rhizome as the leaf sheath.
The iris fan structure compounds the strength of each blade into a sturdy, erect edifice.
---- Fanciata . Term coined by the authors. Basic plicata color pattern except there is an anthocyanin pigmented wash across the ground surface of the falls and standards.
The genotype is two doses of luminata and two doses of plicata allele, also called a “lumiplic,” a shortening of luminata-plicata.
---- Flared . Where the falls stand horizontally as opposed to arched, pendant - hanging downward, or under
Semi flared is used when a slight arching occurs. Flared falls usually occur in cultivars with strong substance and often with erect or open standards. Formerly called fancies or fancy plicatas.
---- Flavone . Yellow or colorless pigment in the cell sap of the central vacuole.
---- Flounces. Long beard appendages with wide, folded blade (petaloid) at its end.
Flounces can be so convoluted, ruffled, and laced they look like a bouquet or rosette. There are so many variations in flounce form that the terminology to differentiate them has yet to be coined. Compounding the problem of describing types of flounces is their great variability in different climate zones and under various cultural conditions.
---- Fluted. Pronounced folds in the petal edges that widen at the top and bottom to nearly touch one another like a Dutch white collar.
This roller coaster fluting greatly exceeds the gentle sinusoidal waves of ruffled petals.
---- Gamete. Germ cells, female ova and male sperm nucleus, that unite to form a zygote.
---- Gametophyte. Gamete or sex cell producing plant in the alternation of generation (back and forth from gametophye to sporophyte) with half the chromosome number of the sporophyte or spore producing plant.
---- Gene . Heredity unit located on a specific chromosome or the cyclic DNA in the mitochondria or chloroplast at a specific locus composed of a segment (or segments) of DNA that encodes a structural, regulatory, or enzymatic protein whose behavior determines a specific genetic trait
---- Gene pool . The sum total of all the alleles of all the genes in a population of interbreeding species plus all the interbreeding cultivar classifications. All the alleles available for iris hybridizers to shuffle to reach a goal.
---- Genome . The sequence of all the nucleotides and genes in all the chromosomes in one complete haploid (1N) set of chromosomes.
---- Genotype . All alleles, either expressed or unexpressed, at all gene loci of a species or hybrid.
The phenotype is only the expressed alleles and how they have responded to the developmental and environmental constraints.
Genotype. All the genetic information of an organism, expressed and not expressed as traits. This is all the information in its chromosomal, mitochondrial, and chloroplast DNA including inserted parasitic DNA as transposons.
The activation of a pollen grain and emergence of the pollen tube in response to the sugar-laden moisture on the stigmatic lip of the style arm.
---- Glaciata . Color pattern lacking all anthocyanin pigments even in the hafts and style arms.
Can be white, cream, yellow, pink, peach, red-orange, and orange in any carotenoid pigment distribution pattern. Formerly called ices for their translucent qualities.
---- Ground. Background base color (cream, yellow, pink, peach, red-orange, and orange) or lack of color (white) produced by the distribution pattern of lipid soluble pigment carotenoids).
Term used in describing plicatas, luminatas, and fanciatas.
---- Hafts . Areas on each side of the narrow base of the falls that extend down each side of the beards.
These visible haft marks plus invisible ultraviolet markings lead pollinators to the nectaries on each side of the base of the falls. Insects and hummingbirds have sensors for these UV patterns. Haft marks serve as guidelines that lead pollinators to the nectaries. These dark haft mark veins can extend in some cultivars different lengths down the falls beyond the beards, even extending the full length of the falls.
Usually, the hybrid iris with such vigor is not sterile like in the case with the mule or triploid or aneuploid iris.
For example, a diploid human with about 25,000 genes has about 5% heterozygosity
---- Heterozygous . Having different alleles at a gene locus.
Gene loci having more than one allele that are different in the traits they express. Condition in a tetraploid iris where the alleles located at the gene loci on the four homologous chromosomes are not the same, such as TTTt, TTtt, and Tttt, or Tt for a diploid.
---- Historic , His. An iris cultivar introduced over 30 years ago.
You would assume that historic also means historic form. This term has lost part of its meaning as there are now cultivars with modern form nearing this birth date. It may be necessary to establish a cutoff year for the historics at about 1977. Soon, over half of the introductions of our top living hybridizers will be historics.
---- Homologous . Meaning the chromosomes have similar structure allowing them to line up and unite in synapses in the second meiotic division.
---- Homozygous . All alleles at a locus are the same.
Condition in a tetraploid iris where all four alleles located at the gene loci on the four homologous chromosomes are the same, such as TTTT, homozygous dominant or tttt, homozygous recessive. In the diploids both alleles, as TT and tt, would be the same.
---- Horns . An upturned appendage (petaloid outgrowth) extending from the distal end of the beards.
This fleshy protrusion often ends in a point. A “fuzzy horn” is covered with short hairs like those in the beards.
---- Hue . Position in the visual spectrum (ROYGBIV) of a color.
---- Hybrid . Offspring of genetically different organisms, such as two species, hybrid and a species, or two hybrids so that the chromosomes arise from more than one wild type species. If the hybrid occurred in nature it called a natural hybrid.
---- Hybridization. Process of producing offspring from two different cultivars or species parents or from one parent by selfing.
IBs are hybrid cultivars derived from crossing SDBs and MTBs, BBs, and TBs that have 16 (2 sets of 8) chromosomes from the SDB parent and 24 (two sets of 12) chromosomes from the MTB, BB, or TB parent for a total of 40 chromosomes. The unmatched sets of chromosomes from the two parents called amphidiploids may not independently assort in meiosis so they behave as if they were diploids, with twice the number of chromosomes. IBs range from infertile, to slightly fertile, or fertile.
---- Increase . Broadly attached, elongate new rhizomatous growths with upright fans that develop at the nodes from flat outgrowths with pointed tips on the sides of the rhizome under the blades.
Increases are called ‘new growths’. The increases formed at the toe end of the rhizome are rounded and bulb-like (called ‘bulblets’) and break off easily like the bulblets of Asiatic lilies or rice of bulbous irises. Bulblets can be broken off or break off naturally to produce new, independent plants.
---- Inflorescence . Upright flowering part of the stem with its basal peduncle, stem branches, paired leaf-like bracts at each node, paired spathes surrounding the flower buds, and flowers on very short internodal stem sections called the pedicels.
---- Infusion. Localized, faint or subtle overlay in the flower of one color on a different base color.
---- Inhibitor. Gene inhibiting the expression of another or other genes, such as the glaciata recessive inhibitor of all anthocyanin color patterns.
---- Internode. Length of stem or stalk between its nodes.
Internodes vary from very short in the rhizome and in flower pedicels, to very long in the developing flower stalk peduncle, and various intermediate lengths in the branches and spur sections of the stalk.
---- Introduction. Advertisement or catalog announcement of a new cultivar properly registered with AIS.
---- Irisarian. Person who grows, collects, and/or hybridizes irises and passionately loves irises for their beauty, diversity, and value as garden plants.
Human being who has a benign case of the iris virus. Citizen of the Iris World or Iris Kingdom sometimes called Irisdom. An iris fanatic is an irisarian who grows more iris cultivars than you do. An irisarian who is “cutting back” is one who is increasing their iris collection at a slower rate and replacing fewer of the cultivars that are lost to natural causes.
---- Kinetochore. Constricted region of the chromosome where the spindle fibers attach. The kinetochore or centromere is the called the primary constriction of the chromosome as some have a secondary constriction.
---- Luminata. Marbled (distributed in streaked manner like in marble) anthocyanin pigmentation that is lacking in the veins, petal edges to various degrees, and around and in the beards.
So far, all luminatas have been shown to have two doses of recessive luminata allele plus two doses of recessive glaciata allele. To date no luminata with four doses of recessive luminata have been demonstrated by test crosses with glaciatas. The luminata pattern may take strong back lighting to delineate the lighter venation in darkly pigmented cultivars. The ground color can be any carotenoid color or color pattern.
---- Lace. The projections from the edges and periphery of the standards, style arms, and falls that can be crenulations (slightly laced), spine-like short to longer pointed projections (laced to very laced), and rounded protuberances (bubble laced).
---- Linkage. When genes are on the same chromosome and are found to have close association based on studies of their inheritance patterns. No genes in irises have been shown unequivocally to be linked.
---- Lycopene. Carotenoid pigment responsible for pink, peach, tangerine, orange, red-orange, and red flower colors.
---- Matte. Flat, non-lustrous surface texture.
---- Megaspore. The larger higher plant spore that develops into the embryo sac inside the ovule, the female macrogametophyte.
---- Meristem. Undifferentiated plant tissue with cells that can develop into other cell types and tissues.
---- Microspore. The smaller higher plant spore that develops into the pollen grain, the male microgametophyte.
---- Midline stripe . Pigmented line down the middle of the falls in plicatas extending from the tip of the beard to the edge of the fall.
Formerly termed a “belly line” by those who did not consider a midline stripe an attractive, enhancing trait, especially when combined with a space age beard appendage.
---- Midrib. The middle of the standards where the vascular tissue in the veins adds support. Also, term used to describe the inner ridge extending down the middle of the style arms.
---- Meiosis. A first division with chromosome replication followed by a second division with reduction to one-half the chromosome number.
In the second division the homologous chromosomes of each set unite linearly (synapse), undergo crossover of segments of chromosomes, and then separate so as to independently assort to each divided cell. Meiosis reduces the diploid (2N) number of sets of chromosomes to the haploid (1N) number; tetraploid (4N) sets are reduced to the diploid (2N) number. In tetraploids compared to diploids meiosis occurs with a higher number of crossover events yielding more potential for diversity of expressed traits in the offspring.
---- Micropyle. Portal for entrance of the microgametophyte pollen tube that passes through the two integument layers and the nucellus of the ovule leading into the embryo sac, the female macrogametophyte.
---- Mitosis. Cell division with the replication of the DNA to form two genetically identical cells performed by the whole cell with disappearance and reappearance of the nuclear membranous envelope.
Mitosis is orchestrated by the spindle fibers that move the divided and condensed chromosomes united in pairs (then called chromatids) to the cell’s equatorial plate and then distribute the chromosomes to each new cell. The phases of mitosis are interphase, prophase, metaphase, anaphase, and telophase.
---- MDB. Miniature dwarf bearded irises , up to 8” (20 cm) tall stalks usually with no branching, the first bearded iris to bloom in earliest spring, the harbingers of spring.
May have dainty, petite tailored flowers. Some modern MDBs have long flowering clumps with multiple buds and even branched stalks, wide and ruffled flowers that form a carpet of color over the short, thin foliage. A few choice MDBs are rebloomers blooming in fall borders in front of and with the taller classes of rebloomers.
---- Moderns . Any iris cultivar introduced in the last ten years, usually with wide and ruffled, modern form.
As modern form reaches its zenith of width, substance, ruffling, fluting, and lace this defined term “moderns” will lose its meaning. This most modern form will become “zenith” form with other flower forms becoming the vanguard of advancement of form in bearded iris. This is presently happening with the need to add to modern form beautiful beard appendages. Stalks with giant single flowers as in Dahlia for florist use and long-pointed spider form as in daylilies may be the new novelty forms and become the new “moderns.” Modern form for each bearded iris classification is what the majority of present day AIS garden judges prefer as mandated by the current judges handbook prepared by the AIS directors and board. The requirements for TBs are the most restrictive and obstructive for encouraging advancements.
---- Moncotyledon . Major grouping of higher seed plants that have only one seed leaf on the germinating embryo, parallel veins in the leaves, flower parts in threes or multiples of threes, and absence of a taproot.
---- MTB. Miniature tall bearded irises, 16-27.5” (41-70 cm) tall stalks, flowers no more than 6” (15 cm) of combined width plus height, that bloom with the tall beardeds (TBs).
Formerly called table irises developed to have no fragrance. Modern MTB cultivars can be rebloomers, possess pleasant fragrances, winter hardy and disease resistant, and play an important role in the garden border and in table arrangements.
---- Mutation. Change in any part of the genetic apparatus of an individual that can be transferred to its offspring.
The change can be in nuclear chromosome structure and number or the chromosomal DNA code, as well as mitochondrial DNA, chloroplast DNA, and plasmid DNA. Also, the genetic change can come from a parasite retrovirus gene converted by reverse transcriptase from RNA to DNA and inserted into the host nuclear DNA, that can change position as a transposon or “jumping gene’. The mutation can be somatic in a nongerminal cell and be transferred to its asexually reproduced offspring, the clone, or in a germinal cell transferred to sexually reproduced offspring, the sporophyte embryo.
---- Nectaries. Areas at the base of the falls on each side of the beards where the nectar is produced that attracts pollinators.
There are six nectaries in each iris flower.
---- Neglecta . Blue-violet or violet bitone with standards a lighter shade of the color of the falls.
In some neglectas the bases and midribs of the standards are nearly as pigmented as the falls.
---- Node. Periodic circular areas of the stem where leaves and new growths or increases are produced.
---- Novelty . Cultivars that maintain unique and unusual features, such as six falls as flat top flowers, having flower parts in fours and fives instead of the regular tripartite form, irregular color patterns as in variegated flowers with streaks and splashes, variegated foliage, having too many or lacking flower parts, such as beards or style arms, having upturned standards and falls like a tulip, possessing spike-like or very long lace, glassy texture that looks wet, having half the flower be white and the other half pigmented, and flowers that will not open completely.
---- Nucellus. Ovule tissue composed of a single layer of cells inside the two integuments that supports the embryo sac, the female macrogametophyte.
---- Octaploid . Cultivar with eight sets of chromosomes in the growing sporophyte plant created by the use of antimitotic agents such as colchicines and Surflan.
Octaploids are usually sterile being unable to produce viable tetraploid gametes. This sterility is caused by the failure of all eight homologous chromosomes to synapse and distribute properly in meiosis.
---- Oncers. An archaic, formerly used colloquial term for cultivars that only bloomed in the spring and did not rebloom.
They are now correctly called spring bloomers (SB) for their outstanding performance in the spring season.
---- Ovary. Enlarged green, three-chambered structure enclosing the ovules where the double fertilization occurs.
In bearded irises the ovary is termed inferior as it is below the other flower parts. The ovary is enclosed in a pair of spathes at the base of this iris flower that is termed perfect as it has both male (stamen) and female (pistil) parts.
---- Ovules. Ovoid structures in the ovary containing the ova that when fertilized develop into seeds.
An ovule has sporophyte coverings, two integuments and the nucellus that surround the embryo sac (macrogametophyte) that contains the egg cell and two polar cells. The ovule is connected to the central placenta of the ovary by a slender feeding tube, the funiculus. The egg cell unites with one sperm nucleus to form the zygote that develops into the sporophyte embryo. The two polar cells unite with the other sperm nucleus to form the endosperm nourishment material that feed the embryo as it germinates. This double fertilization
is unique to higher green plants
---- Pedicel. (pedal it cell) The very short stalk of the flower extending to the base of the ovary.
---- Peduncle. The long basal stalk of the iris inflorescence (flower stalk) capped by a large bud, the spathe enclosed flower cluster, that develops by elongation of its stalk trunk, offshoot branches, spur, and terminal bud stalk.
---- Peppering. Stippled small dots of anthocyanin pigmentation on the falls associated with the plicata and other patterns, and in some cultivars spreads across the falls.
---- Perianth. Term for the combined three falls (sepals) and three standards (petals).
Irisarians often use the convenient term “petals” for the perianth.
Under Construction. See Attached original at beginning of page
- 12 Feb 2019