Corresponding author: W. John (
Academic editor: Sandra Knapp
The classification of the family
In 1835 Nathaniel Wallich applied the name
In Wallich’s 1835 original application of the generic name, the genus honored Mr. Thomas Hitchin of Norwich, England, who was a gardener and distributor of rare plants in the 1810–1830s (
Since the time of Baker, little progress has been made in understanding the taxonomic status of
In 2002, as part of a survey of the gingers of Myanmar, one of us (WJK) collected specimens of an unknown ginger near Myitkyina, in Kachin State, which closely resembled
After studying both living specimens and preserved collections of all four taxa, the accumulated research data were sufficient to warrant the circumscription of a new genus. The long exserted and arched style (with included filament) of the flower resembles a similar floral structure found in genera such as
With regards to the remaining species in the genus
Below we provide descriptions of the new genus and the four included species. Plant measurements were for the most part recorded from living material. Methods and results of the molecular phylogenetic analysis, GenBank accession numbers for a three-locus DNA barcode for each species, and assessments of the conservation status of all species of
Total genomic DNAs were extracted for a representative sample of each species of
Newly generated sequences of the
Analyses of the ITS data matrix produced 23 shortest trees of 1,011 steps based on 268 parsimony informative characters (results not shown). Trees fell into three distinct tree islands, one of 21 trees, and two of one tree only. Differences between these three tree islands were minor. In all shortest trees, the four species of
The combined data analyses produced 18 shortest trees of length 1,590 steps (
The DNA barcodes that were generated for the three barcode loci,
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trnK (including matK) | rbcLa | trnH-psbA |
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W. J. Kress 10-8750 (US) | HM771392 | HM771404 | HM771400 | HM771396 |
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W. J. Kress 03-7403 (US) | HM771393 | HM771405 | HM771401 | HM771397 |
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S. Dey 1012 (CAL) | HM771395 | HM771407 | HM771403 | HM771399 |
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Sanoj & Rajesh Kumar 105640 (CAL) | HM771394 | HM771406 | HM771402 | HM771398 |
Molecular phylogeny of the
The overall distribution of the genus covers a large area of sub-Himalayan forests in northeastern Bangladesh, the Indian states of Meghalaya and Assam, the northern border of Arunachal Pradesh, and into upper Myanmar.
Evergreen, rhizomatous, terrestrial herbs, clumping with 10–20 shoots per plant, 1–2.5 m tall, plane of distichy of leaves parallel to rhizome, 2–12 leaves per shoot, alternate, sessile to petiolate. Inflorescence terminal on leafy shoot or basal on leafless shoot, pedunculate; bracts basally attached, reflexed or adpressed, spirally arranged and imbricate, 35–80 per inflorescence, not pouched, adventitious plantlets sometimes produced in sterile bracts at base of inflorescence; flowers mature from base to apex of inflorescence. Bracteoles variable in size, the inner one largest, not tubular. Flowers conspicuous, in cincinni of 2–6 flowers or rarely reduced to one flower; calyx tubular, tri-dentate, shorter than the corolla; floral tube long and curved, exserted well beyond the bract, corolla lobes subequal with dorsal lobe slightly larger than laterals, apex opening oblong, bordered on the two lateral sides with a thickened and rounded margin formed by the base of the lateral staminodes and the labellum; lateral staminodes small, bowl-shaped, reflexed; labellum narrow at the base, widening towards the apex, elongate, oblanceolate or spatulate, basal margins thickened, raised with center channeled or ‘v’ in cross-section, apex dentate or entire; fertile stamen long and arched over the labellum, anther oblong, without a crest, thecae dehiscent for full length; epigynous glands linear; style with stigma protruding beyond anther thecae; ovary trilocular, fruit an oblong capsule, two-layered with the outer splitting into three coiled sections, the inner forming an arillate membrane covering the 1–10 seeds.
This new genus honors Dr. Kai Larsen, Professor of Botany Emeritus, Aarhus University, Denmark, for his many years of dedicated efforts in the education of botanists worldwide and for his profound achievements in the taxonomy of the family
.
1b. | Inflorescence terminal on a leafy shoot | 2 |
2a. | Inflorescence bracts green and white, 4–6 flowers per bract |
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2b. | Inflorescence bracts red, 1–3 flowers per bract | 3 |
3a. | Margins of inflorescence bracts corrugate and denticulate, 1 flower per bract |
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3b. | Margins of inflorescence bracts entire and smooth, 2–3 flowers per bract |
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Known only from the type locality in Kachin State, upper Myanmar.
This species is found in the understory of evergreen forests dominated by members of the family
Named for Francis Kingdon-Ward, the British plant collector who extensively explored Upper Burma in the first half of the twentieth century and who inspired the authors of this species in their work in Myanmar (
Known from the type collection in Padaung National Park west of Myitkyina, Kachin State, Myanmar, as well as cultivated material (Smithsonian Botany Research Greenhouse GH-2002-050) collected at the type locality.
Bangladesh and northeastern India (Assam, Meghalaya, Arunachal Pradesh, Manipur).
This species was originally named by Wallich for the botanist Dr. William Carey (1761–1834).
Known only from two locations in the Barail Wildlife Sanctuary.
This species occurs in the understory of tropical semi-evergreen forest in very moist conditions along streams (rainfall 350–400 cm/yr) at 25–150 m in elevation. Associated plants are species of
Named for the Indian state of Assam where this species is endemic.
Inflorescences with flowers of
This species grows in sandy soil above 1,400 m in elevation amidst thick clumps of wild species of
The specific epithet “arunachalaensis” is derived from the name of the state in northeast India from where the type specimen was collected.
Known only from the type specimen.
We would like to acknowledge Mark Collins, Mike Bordelon, Linda Van Vorobik, Alice Tangerini, Ida Lopez, Jana Leong-Škorničková and Mark Newman for helpful discussion and assistance in preparing the manuscript; colleagues in Myanmar, India, and Bangladesh, especially Mr. Rajesh Kumar, Mr. Satyanarayananji, and U Thet Htun, for assistance in the field; Dr. Philip Oswald and Dr. Alain Touwaide for the Latin diagnoses; and especially Prof. Kai Larsen for his many contributions to our understanding of the taxonomy of the family
Funding support was provided by a research grant from the Department of Science and Technology, Govt. of India, New Delhi (SP/SO/PS/115/2009), a Senior Research Fellowship awarded by the Council of Scientific and Industrial Research (CSIR), New Delhi, (9/43(0138)2K9-EMR I), and the Smithsonian Institution. All are gratefully acknowledged.