How to Write Binomial Names

1. Binomial names are usually typeset in italic, e.g. Zea mays, ;

or any other font different from that used in the normal text, e.g. “Zea mays is a facultative long-night plant.”

2. when handwritten, each part of a binomial name should be underlined, e.g. Zea mays.

3. The genus name is always written with a initial capital letter, the specific epithet is never with an initial capital.

4. When used with a common name, the scientific name often follows in parentheses, e.g. “Maize (Zea mays) has 10 chromosomes.”

5. The binomial name should generally be written in full.  The exception to this is when several species from the same genus are being listed, or the same species is mentioned repeatedly, in which the genus is written in full when it is first used, but may then be abbreviated to a capital initial and a full stop.  e.g.  Zea diploperennis and Z. perennis are perennial, while Z. mays, Z. luxurians and Z. nicaraguensis are annual.

In care cases, this abbreviated form has spread to more general use, e.g. Escherichia coli is often referred to just E. coli, and Tyrannosaurus rex is better known as T. rex.

6. The abbreviation ‘sp.’ is used when the actual specific name cannot or need not be specified.  The abbreviation ‘spp.’ indicates plural form.  These abbreviations are not italicized or underlined.  e.g. Canis sp. means “an unspecified species of the genus Canis”, while Canis spp. Means “two or more species of the genus Canis”

7. Infraspecific name

When use a connecting term ( subsp., var., c.f., f. etc ), it is customary to italicize all three part of such a name, but not the connection term.

a. ‘subsp.’, plurals ‘subspp.’ for subspecies, e.g longbean - Vigna unguiculata subsp. Sesuipedalis

b. ‘var.’ for varietas (variety) , e.g Broccoli - Brassica oleracea var. botrytis

c. ‘subvar.’ for subvarietas (subvariety) , e.g Chinese cabbage – Brassica rapa subvar. pekinensis

d. ‘cv.’ for cultivated varietas (variety) , e.g Durian -  Durio zibethinus cv. D24, or Durio zibethinus ‘D24’

e. ‘f.’ for forma (form) , e.g Bishop’s cap cactus - Astrophytum myriostigma f. quadricostata

f. ‘subf.’for subforma (subform) , e.g. Saxifraga aizoon subf. surculosa

8. The abbreviation ‘cf.’ comes from the Latin word conferre, which means “compare to”.   It is used when the identification is not confirm, e.g. Crovus cf. splendens, indicates “a bird similar to the house crow but not certainly identified as this species.”

9. The symbol ‘†’ placed before or after the binomial name indicates that the species is extinct, e.g. † Nelumbo aureavallis.

10. A hybrid is often named with few options :

a. normal botanical name, e.g. Iris albicans

b. a ‘x’ placed before the specific epithet for interspecific hybrid, e.g. Citrus x floridana ( C. aurantiifolia x C. japonicas )

c. a ‘x’ placed before the generic name for intergeneric hybrid, e.g. x Heucherella tiarelloides ( Heuchera sanguinea x Tiarella cordifolia )

11. A graft-chimaera :

a. a ‘+’ placed in between both parents. e.g. Crataegus + Mespilus

b. a ‘+’ placed before a newly-formed name for intergeneric grafting. e.g. + Crataegomespilus (Crataegus + Mespilus)

c. a cultivar name is given for interspecific grafting, e.g. Syringa ‘Correlata’ ( Syringa vulgaris + Syringa x chinensis )

ICZN, International Code of Zoological nomenclature

ICN, International Code of Nomenclature for alge, fungi and plants ( formerly ICBN )

ICNCP, International Code of Nomenclature for Cultivated Plants

ICNB, International Code of Nomenclature of Bacteria

ICTV, International Committee on Taxonomy of Viruses