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A cultivar is a selected assemblage of cultivated plants that remains distinguishable, sufficiently uniform and stable in specified characteristics when maintained by appropriate plant propagation. The characteristics may concern form, colour, flowering or other useful traits. A cultivar is a named cultivated selection, rather than simply any individual growing in a garden.^[ref]

The phrase “appropriate propagation” matters. Some cultivars are maintained by vegetative propagation, while others can be maintained through seeds or a repeatable hybrid cross. A cultivar therefore need not consist of just one plant clone.^[ref]

For an illuminating example, suppose a selected plant has a distinctive flower colour. Producing more plants is insufficient if their flowers lose that distinguishing trait. The propagation procedure must retain the relevant combination of characteristics. Conversely, variation in an unselected feature need not invalidate the selection: “uniform” concerns the characteristics that distinguish the cultivar, not absolute identity in every measurable property.

Malus is the taxonomic genus of apples and crabapples in Rosaceae. Its members are deciduous shrubs or trees. Their flowers have numerous stamens and several fused carpels; the mature fruit is a pome, with fleshy tissue surrounding the seed-bearing core. The genus name covers related wild and cultivated plants, whereas an individual cultivar identifies a selected cultivated form.^[ref]

A useful identification exercise follows one flower into one fruit. A transverse cut through a familiar apple exposes the chambers of the core; a longitudinal cut connects them to the stalk and persistent floral parts. The firm chamber walls and the surrounding flesh are distinguishable tissues. Comparing them with the single hard stone of a peach connects differences in mature fruit to differences in carpel arrangement.

Small ornamental crabapples and large eating apples can both belong to Malus. Size or culinary use alone therefore does not define this taxonomic genus. Floral and fruit structure provide a biological comparison across plants selected for very different purposes.^[ref]

A plant clone is a lineage of plants descended from one founder by asexual reproduction. Vegetative propagation, for example rooting several plant cuttings from one stock plant, can multiply a selected genotype while avoiding the reshuffling associated with ordinary sexual reproduction. This is why such methods are useful for maintaining a named cultivar that does not reproduce its characteristics reliably from seeds.^[ref]

A plant clone is defined by descent, not by identical appearance. Its members can experience different light, water or nutrient conditions, and somatic mutations can arise during growth. Shared ancestry consequently does not imply that every phenotype or every later DNA sequence must remain identical.

For an illustrative experiment, divide rooted plant cuttings from the same founder between brighter and dimmer conditions while keeping other conditions comparable. Differences in leaf size need not establish a difference in inherited genotype: the design deliberately holds ancestry relatively constant while changing the environment. Repeating this across several distinct plant clones can test whether different genotypes respond differently, an example of genotype-environment interaction.

Plant propagation is the production of new plants, including establishment from seeds and multiplication by vegetative propagation. The choice of method matters: ordinary sexual reproduction reshuffles inherited material, whereas vegetative propagation preserves a parental lineage as a plant clone. Thus a named cultivar need not retain its distinguishing features when grown from its own seeds. Plant propagation is broader than either germination or vegetative propagation. ^[ref]

For an illustrative comparison, imagine sowing ten seeds from one parent and rooting ten plant cuttings from that parent. Both procedures can increase the number of plants, but they answer different questions. The seedlings sample offspring produced through fertilization; the rooted plant cuttings can supply repeated representatives of one plant clone. Recording the starting material is therefore essential before treating differences among the resulting plants as differences among inherited genotypes.