Typification (ICBN Art. 7-10)

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Typification (ICBN Art. 7-10)

• Type concept Each plant name must have a
  physical representation permanently associated
  with it (usually a specimen, but note exceptions)
  
• Types are essentially name standards

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Typification

• type concept not developed before Rochester Code
  (1892)
• developed and promoted by N.L. Britton (NY) not
  adhered to by Europeans at first

N.L. Britton (NY)
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Note collection number
Ignatz Urban (B)
Erik Ekman
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Designation of type
Symbolae Antillanae 9(3) 422-423. 1925.
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Why are types important?

• Practical serve as diagnostic standards of
  comparison for other specimens
• Nomenclatural provide stability, leading to a
  regulated and unambiguous nomenclature

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Types of types

• Holotype (HT) the specimen or single element of
  a collection designated or indicated by the
  author as the type specimen of a taxon in the
  protologue.

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Types of types (contd)

• Syntype (ST) (1) any of two or more collections
  cited by author in the protologue when no
  holotype was designated or (2) any of two or more
  specimens designated as types.

Example Follicle 12-15 cm x 2-3 cm. Seeds
obovate, brown, 4.3-5.4 x 2.3-3.3 mm. Ekman 123
(S, NY) Sloane s.n. (BM) Brown (K).
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Types of types (contd)

• Isotype (IT) any duplicate of the holotype
  (i.e., part of the same collection).
• Example 1 Ekman finds a new species of milkweed
  and collects enough for two sheets. In the
  protologue of the new species, Urban designates
  Ekman 14453 as the type and deposits it at the
  Swedish Museum of Natural History (S). He sends
  the other sheet to the New York Botanical Garden
  (NY). The material at S and NY are isotypes.
• Example 2

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Types of types (contd)

• Lectotype (LT) a specimen selected by a
  subsequent author from amongst syntypes to serve
  as the definitive type for a name.

Example First Author Follicle 12-15 cm x
2-3 cm. Seeds obovate, brown, 4.3-5.4 x 2.3-3.3
mm. Ekman 123 (S, NY) Sloane s.n. (BM) Brown
(K). Revisionary Author Sloane s.n. (LT
BM!).
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Types of types (contd)

• Neotype (NT) a specimen chosen by a subsequent
  author to serve as the type, when all original
  material has been lost or destroyed.

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Typification issues

• Easily applied to newly discovered species,
  however, the typification of older names often
  proves problematical for a number of reasons
  
• unified concept of typification not codified
  until 1930
• the physical destruction of collections (through
  fire, war, flood, neglect)
• the loss of records regarding the location and
  origin of specimens (through sale, neglect,
  accident)