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Natural History Highlight
    Discovery of a New Plant Genus  (January, 2002)
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Photo: ginger flower
The flower of Smithatris supraneeana,
Photo by Michael Bordelon
. (Click here for larger image.)

NMNH Botanist W. John Kress and his colleague Kai Larsen, University of Aarhus, Denmark, have named a new genus of ginger.  Discovery of a new plant genus is unusual, unlike the more frequent naming of a new species.  The new genus Smithatris, in the plant family Zingiberaceae, joins 50 other genera and over 1,200 species.

Kress first noticed the new ginger in a flower display in Singapore, and then it was collected in the wild in 1998 in the limestone hills in the Saraburi Province north of Bangkok, Thailand.  The new genus and species, Smithatris supraneeana, was described based upon the study of plants in the field, greenhouse, herbarium, and laboratory.  Mike Bordelon, Manager of NMNH's Botany Research Greenhouses, was able to bring to flower living material of the new genus.  Botanical illustrator Alice Tangerini used those flowers as a model for the definitive scientific drawings of the new genus and species.  (Click here to see the illustration of Smithatris supraneeana.)  Molecular DNA sequence data support the placement of Smithatris with the genera Curcuma and Hitchenia (tumeric and relatives), but clearly differentiates it from each of these genera. Voucher specimens documenting this discovery are now in the US National Herbarium and in cultivation in the NMNH's research greenhouses.  Kress and his Danish colleague  Kai Larsen published  their discovery in the article "Smithatris, a new Genus of Zingiberaceae from Southeast Asia" in Systematic Botany (2001), 26(2):pp-226-230.  Interestingly, they predicted that this genus should also be found in the adjacent areas of Myanmar where similar habitats exist.  This past summer, Kress and Bordelon discovered a second species of Smithatris in that country, north of Mandalay. 

How Are New Plant Genera
Found?

Occasionally new plant genera are found in the wild. More frequently, however, new genera are identified in the laboratory as a result of molecular genetic studies. These studies examine the genetic relationships among plants using DNA, and can determine whether plants that look alike really are the same genetically.

How Often are New Genera
Found ?

The answer is ... "it depends". It is very rare to discover a new genus of mammals, but much more common to discover a new genus of bacteria. Kress estimates that for every 1000 new species discovered in the plant kingdom, someone will discover one new genus. Discovery rates also depend upon the part of the world under study.

Map of Thailand
Saraburi Province is indicated by the marker
just above Bangkok and Ayutthaya.

Map from Microsoft® Encarta® used by permission
of Microsoft Corporation. (Click here for larger map.)

When flowering, Smithatris supraneeana is commonly sold in large quantities in Saraburi-area markets near the renowned temple Phra Putthabat or "Footprint of Buddha".  The flowers are used in the temple during the Buddhist lent.  In Bangkok this species is sold in flower markets under the commercial name "Siamese Platinum" and is now also available in the international horticultural trade.  Kress notes that "... the fact that this ethnobotanically important plant has remained unknown to taxonomists until now suggests that our knowledge of the flora of tropical Asia is still rudimentary."  

What’s in a Name?

The scientific name of an organism, whether it is a plant, animal, virus, or bacteria, reveals a lot of information about that organism’s relationship to other living things. Here’s an example of how Smithatris fits in the plant kingdom naming scheme, and a comparison to an organism in the animal kingdom:

Kingdom: Plantae (all green plants)
Division: Tracheophyta (vascular plants)
Subdivision: Spermatophytina (seed bearing plants)
Class: Angiospermae (flowering plants)
Subclass: Monocotyledoneae (plants with one seed leaf)
Order: Zingiberales (gingers, bananas, prayer plants, cannas)
Family: Zingiberaceae (plants particularly known for the presence of aromatic oils)
Genus: Smithatris
Species: supraneeana
Kingdom: Animalia (all animals)
Phylum: Chordata (animals with a notochord)
Subphylum: Vertebrata (animals with a vertebral column or "backbone" instead of a notochord)
Class: Mammalia (animals with fur and mammary glands who lay eggs or bear live offspring)
Subclass: Theriiformes (all mammals except those that lay eggs) 
Order: Carnivora (animals with sharp grasping claws, and teeth adapted to stabbing and cutting meat) 
Family
: Canidae ( dog-like carnivores adapted for long distance pursuit of prey)
Genus: Canis (includes all wild dogs such as dingos, jackals, and wolves)
Species: familiaris (domesticated dogs)

The process of determining the correct name for an organism is time consuming and requires the use of scientific literature. To give Smithatris its name, Kress and Larsen searched through all the scientific publications about gingers. They also examined plant specimens in the NMNH herbarium and borrowed plant specimens from other herbaria around the world. In each case, the scientists examined the specimen and considered the plant’s features that were given in its formal description. Finally, after comparing Smithatris with all the other described gingers, Kress and Larsen decided that its uniqueness warranted a new genus. A molecular DNA study performed at the NMNH’s Molecular Systematics Lab confirmed that Smithatris was different from other gingers.

The method of describing plants has been established by the International Code of Botanical Nomenclature. Botanists the world over follow the Code, including the requirement that a type specimen be permanently deposited in an herbarium.  The "type specimen" is the preserved plant that serves as the authoritative example of the species.  The voucher documents the discovery.  A formal description, or at least a diagnosis,  of all newly named plants must be provided in Latin; however, a more lengthy, detailed English description often accompanies the Latin. 

DESCRIPTION:

Smithatris supraneena W.J. Kress & K. Larsen, gen. et sp. nov. (Figs.1-3).- TYPE: THAILAND. Saraburi: 16°45N, 100°50E. Limestone mountain at ca. 200 m elevation. 5 September 1998, K. Larsen 47207 (holotype: BKF!; isotypes: AAU!, PSU!, US!).

Herba Curcumae et Hitcheniae similis, Hitcheniae similior foliis petiolatis, inflorescentia pedunculata bracteis congestis saccatis, tubo corollae longo, sed differt labello profunde fisso, structura cucullata staminodiis lateralibus formata et lobo dorsali corollae antheram partialiter includenti.

English translation of the Latin: An herb similar to the genera Curcuma and Hitchenia, similar to Hitchenia in its petiolate leaves, pedunculate inflorescences with congested, pouched bracts, and long corolla tubes, but differing in the deeply lobed labellum, hooded lateral staminodes together with the dorsal corolla lobe partially enclosing the anther.

Drawing of ginger flower
The flower of Smithatris supraneeana,  
Illustration by Alice Tangerini.
(Click here for larger illustration.)


To learn more about this research, botany, and the US National Herbarium, visit these sites:


NMNH Department of Systematic Biology, Botany
http://botany.si.edu/

NMNH Department of Systematic Biology, Botany, Collections
http://botany.si.edu/?collections

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January 2002  NMNH Webmaster

"Natural History Highlight" features interesting and exciting activities and objects from the Museum.  We will frequently introduce new highlights that come from our research, collections, exhibits, and projects.      
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