Boesenbergia longiflora (Zingiberaceae) and descriptions of five related new taxa

Fig. 16. Boesenbergia hamiltonii Mood, S.Dey & L.M.Prince. A. 

First-day flower. B. First-day 

flower. C. Mature plant. D. Rhizome and tuberous roots. All photos of Dey NU53. (Photos: J. 

Mood)

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(thecae diverging on the second day) apex truncate to slightly bilobed with no anther 

crest, thecae 10

-12 × 1 mm, white, dehiscing along the entire length. Ovary c. 5 × 

4 mm, trilocular, axile placentation, white, glabrous; style 

filiform, white, glabrous, 

stigma elongate, ostiole vertically rectangular, without cilia, exuding a sticky liquid on 

the second day; epigynous glands narrowly ovate, two, 5 mm long, tan-white. Fruit a 

capsule, cylindrical, asymmetrical, 2  cm long, 1 cm wide, calyx and floral tube remain 

partially intact, white, glabrous, surface smooth; seed globular, slightly flattened, apex 

rounded, tan-yellow, aril sparse, white, translucent. (Measurements based on living, 

wild material at the type location in India of Dey NU53).

Distribution. This taxon has been recorded primarily in Meghalaya and hill areas of 

Assam. Its full range has not been determined. 

Ecology. This species is normally found in sloped habitats where there is some shade, 

good soil moisture and excellent drainage. Most plants are seen along roadside banks 

on forest margins or more rarely in open forests. Observed elevations range up to 500 

m asl, although Rao & Verma (1974) reported elevations up to 1850 m asl. The type 

specimen was found growing under light shade in deep, black, well drained soil on the 

margin of a disturbed secondary forest at 350 m asl. Associated plants were Shorea 

robusta  C.F.Gaertn.,  Tectona grandis L.f., Musa species, bamboo and understory 

herbs. 

Phenology.

 Flowers from May to September with a two-day flowering cycle for each 

flower.

Etymology. Named for Francis Buchanan Hamilton (1762

-1829) a Scottish surgeon 

and botanist in the employ of the East India Company from 1794

-1815. His botanical 

research, collections, geographic documentation and statistical surveys provided a solid 

foundation for future explorers and botanists in Northeast India, Burma and Nepal. He 

served as Superintendent, Calcutta Botanical Gardens between 1814

-1815. His two 

specimens of Bangleum sulphureum

 from 1808 appear to be the first collections of this 

new taxon. 

Additional specimens examined: BANGLADESH: 

Sylhet  Division. Laour, Jun 1830, 

Gomez in Wallich 6579B (K-W; *). INDIA.

 Assam. Camrupa, 21 Jul 1808, Hamilton 12 (E; 

*); Goalpara, Hamilton s.n. (Wallich 6579A, K-W, CAL); no location, no date Jenkins s.n. 

(ASSAM); Kamrup Dist., 13 Jun 1964, Rao 38791 (ASSAM; *); Darrang, Batasipur, 12 May 

1947, 

Srinivasan 22411 (ASSAM);Tangla, 24 May 1958, Nath 13387 (ASSAM); Sibsagar, 

Panbari, 15 Jun 1963, Deb 34846 (ASSAM). 

Meghalaya.  Nongpoh, 31 Jun 1964, Joseph 

37477 (ASSAM; *); Nowgong Dist., 18 Aug 1964, Balakrishnan 39222 (ASSAM); Nowgong 

Dist., 31 Aug 1938, De 20327 (ASSAM); Nowgong Dist., 25 Aug 1964, Balakrishnan 39415 

(ASSAM); Khasia Hills, J.D. Hooker s.n. (ASSAM, C; *); Garo Hills, 6 Sep 1962, Deb 29216 

(ASSAM); Khasia & Juanita Hills, 4 Jul 1938, De 20326 (ASSAM); Khasia & Juanita Hills, 8 

Jun 1939, Deka 19668 (ASSAM); Khasia & Juanita Hills, 4 Jul 1940, Deka 20236A (ASSAM); 

Khasia & Juanita Hills, 23 Jun 1941, De 21089 (ASSAM; *).

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Boesenbergia longiflora and related taxa

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Fig. 17A & B. Flowers. Left: Boesenbergia collinsii (M3035); Centre: B. kerrii (M2044); 

Right: 

B. longiflora (M11P48). (Photos: J. Mood)

Notes. This species is distinguished from B. kingii by the small, short rhizome with 

long, vertical tuberous roots which usually produces only a single, robust pseudostem 

(Fig. 16D). Indicative of this below-ground morphology, B.  hamiltonii is easily 

recognized in the field by the widely scattered, individual plants, occurring in a low-

density population of seeded individuals (Fig. 16C). In contrast, B.  kingii  occurs in 

multi-stemmed, high-density populations of clonal and seeded individuals (Fig. 15C, F). 

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Fig. 18A & B. Flowers. Left: Boesenbergia maxwellii (M11P124); Centre: B. kingii (M11P77) 

Right: B. hamiltonii (M3209). (Photos: J. Mood)

The flower colour of B. hamiltonii is pure white with a red, maculate throat and a 

pale pink lip apex. Colour variations between populations are primarily in degree of 

pigmentation. When the labellum is dissected and flattened, it is very similar in shape 

to B. kingii, but in living plants the full open, frontal shape is oval in the former and 

truncate or rounded in the latter. As a historical note, after Hamilton collected his two 

(Banglium) specimens in 1808, he used “sulphureum

” (light yellow) as the specific 

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