Under the microscope normal chromosomes look like miniature paired sausages, having two arms branching out from a narrow center. These are the so-called called metacentric, i. e. "middle-centered"chromosomes.
Accidental breaks result in single arms with the nominal "center" attached to one end.
Such fragments are termed telocentric, i. e. "end-centered".

The image shows the chromosome set of Paphiopedilum chamberlainianum. Half of the set inherited from one of its parents is lined up neatly to illustrate the details. There are 9 normal chromosomes having two arms plus seven fragments of arbitray length.

9+9 M(etacentrics) and 7+7T(elocentrics) result in 2(times)n(umber)=32 (18M+14T)

During fertilization matching then fusing such chromosomes is a highly stochastic molecular process, inevitably resulting in mismatches. Minor or not-so-minor differences will abound in the offspring Notice that data for P. chamberlainianum treated here differ from data shown on the picture but are matching numbers observed in P. primulinum. Chromosome sets of Paphipedilum glaucophyllum individuals may and often do differ - and so on and on.