Dendrobium Swartz Section Herbacea Kränzlin (Orchidaceae)

2007·2.1 MB·

by  Wood, Howard P

Selbyana 28(2): 117-122.2007.
DENDROBIUM SWARTZ SECTION HERBACEA KRANZLIN
(ORCHIDACEAE)
HOWARD P. WOOD, M.D.
Associate in Botany, Academy of Natural Sciences of Philadelphia, Philadelphia, PA 19003, USA.
Correspondence: 3300 Darby Road C-802, Haverford, PA 19041, USA.
Email: [email protected]
ABSTRACT. Dendrobium Sw. Section Herbacea Kraenz!. is revived for two Asian species, Dendrobium
herbaceum Lind!. and D. parcum Rchb.f. Definitive characters are branching, deciduous habit; short, few
flowered racemes arising from the branches, often apparently terminal; and small simple flowers with
decurved saccate mentum. The type species is D. herbaceum. There appears to be a third, unidentified,
species.
Key words: Orchidaceae, Epidendroidere, Dendrobiinre, Dendrobium herbaceum, D. parcum, D. ramosis
simum, section Herbacea
Two species of Dendrobium have never fit 1981, Joseph 1987). It is evidently common in
well into any of the sections of the genus in the Western Ghats, although I have not seen or
current use. These are Indian D. herbaceum read about its cultivation in the West. The best
Lindl. (1840) and Southeast Asian D. parcum drawings among the above sources appear in
Rchb.f. (1866). These plants are similar and Pradhan (1979) and Abraha= and Vatsala
very distinctive, with multiple upcurving, linear (1981).
to fusiform branches, leafy on the terminal Dendrobium herbaceum may reach 90 cm (35
branches or branchlets only, and usually decid inches) in height. The flower has lip down
uous before flowering. The leaves are acumi curved and constricted near the middle, with the
nate; the roots are smooth. Short racemes bear proximal edges slightly rolled upward, forming
up to about 5 flowers, each 1 cm or less in di rudimentary side lobes. The blade is ovoid,
ameter. The inflorescences usually appear to be coming to a blunt point. The flowers are de
terminal on the leafless branches, but may also scribed as green (Lindley 1840), greenish-white
be lateral. The flowers have a deflexed, saccate (Santapau and Kapadia 1966) and pale yellow
mentum and prominent lip. In D. parcum the (Joseph 1987). Abraham and Vatsala (1981) de
column is short, rostellum bifid, anterior surface scribe them as white with a yellow lip (FIGURE
of the column foot hollowed and broadened 3). As discussed below, some authors may be
around and below the orbicular stigma. The pol referring to a third species.
linia are unusually short and broad for the genus. Apparently unaware of Lindley's taxon, Rob
Drawings of D. herbaceum, in the references cit ert Wight, surgeon-botanist for the East India
ed (FIGURES 1, 2, 3), show similar features. The Company in Madras, described from dried ma
only obvious distinguishing character among the terial a (misspelled) D. ramossissimum ("very
species, including an unnamed entity discussed branched") (FIGURE 4). The description and
below, is lip structure. drawing (FIGURE 5) in his leones are labeled, t.
Dendrobium herbaceum ("yellow-green"), 1648 (Wight 1852). Below, following Lindley, I
described by John Lindley (1840), is endemic to refer to his drawing as "R. W. t. 1648." The
the peninsula of India. Although reported from specimen, now in Wight's herbarium at Kew,
other locations, this species typically inhabits the had been collected by Jerdon in the Coorg (now
Western Ghats, the range of mountains extend Koorg) jungles in the Western Ghats, midway
ing the length of the west coast of the peninsula. down the peninsula. Wight's detailed drawing
Lindley sketched the lip shape clearly on his shows the distinctive lip of D. herbaceum. He
type sheet (FIGURE 2), where he noted that the describes the flowers as yellow.
specimen had been imported by the firm of Lod Lindley's sheet of D. ramosissimum (he cor
diges from the "East Indies," a term which in rected the spelling) is in his own herbarium, now
those days included India. This species is dis kept separately at Kew (FIGURE 6). It contains
cussed, with drawings but without photographs, not Wight's but two later specimens. Indicating
in subsequent literature on the orchids of India that he (incorrectly) considered it a type, Lindley
(Hooker 1890, Fischer 1928, Santapau & Ka attached a label across the base of the stem of
padia 1966, Pradhan 1979, Abraham & Vatsala the plant on the right, marked "R. W. Ie. 1648"
117
118 SELBYANA Volume 28(2) 2007
FIGURE 2. Dendrobium herbaceum Lindl., type
sheet drawing, enlarged detail.
FIGURE 1. Dendrobium herbaceum Lind!. type Wight described and figured. In addition, Abra
specimen; published with permission from The Royal ham and Vatsala (1981) show, for one of the two
Botanic Gardens, Kew.
flower specimens of "D. herbaceum" in their
sketch, the lip distally expanded and grooved.
This flower resembles that of the Ker plant.
and noted its ongm as "Dalzell, S. Concan Lindley, seven years after Wight's description,
R.160, 52 Herb J. E. Stocks." Labeling this commented on D. ramosissimum: "This is very
specimen in a manner he reserved for types near my D. herbaceum (Lindley 1840, Bot. Reg.
seems to be one of several uncharacteristic mis 1840, misc. 153), but the flowers are white with
takes in Lindley'S late work on the Dendrobi a yellow lip, not white tinged with green; the lip
inae, including the 1859 paper. These may be itself is longer and more fleshy, and the flowers
early signs of his fatal dementia. His mental are considerably smaller. I have examined fresh
powers failing, he retired from his professorship specimens out of Mr. Bellenden Ker's garden
in 1861, had a "breakdown" in 1862 and died from Dharwar." (Lindley 1859). Dharwar, now
in 1865 (Stearn 1991, 1999). Hubli-Dharwar or Hubli, is a city 400 kIn (250
Although Lindley (1859) kept the two taxa mi) southeast of Bombay, east of Koorg. For the
separate on unclear grounds, the type sheets in (erroneous) type reference, in his 1859 paper
dicate that D. ramossissimum Wight is a syno Lindley writes, "S. Concan, Dalzell in hb.
nym of D. herbaceum Lindl. I am retaining both Hooker. (Stocks, 52)." Thus the right-hand spec
spellings, Wight's and Lindley's, for purposes of imen on Lindley's sheet, Stocks 52, came from
clarity, since two taxa seem to be involved and, the Hooker herbarium, and Lindley seems to
indeed, the name in either case is illegitimate. have incorrectly considered it his lectotype for
The plant on the left side of Lindley's sheet D. ramossissimum Wight. The Ker plant on the
for Dendrobium ramosissimum is marked, "H. left and in the drawing is obviously one of those
B .. Ker, Dharwar." Adjoining it in the center, and which Lindley received alive and described in
similarly labeled, is a drawing of a white flower the quotation above. Thus I believe that it rep
with a straight, fleshy, rounded lip. The blade is resents a still-undescribed species, which I will
yellowish brown with a medial groove extending call "D. ramosissimum sensu Lindley, non
to the tip. The rudimentary sidelobes are slightly Wight."
uprolled. This plant is certainly not the taxon George Bentham and J. D. Hooker (1883),
WOOD: DENDROBIUM SECTION HERBACEA 119
FIGURE 3. Dendrobium herbaceum drawing in Abraham and Vatsala "1981." Introduction to Orchids. Fig.
91, p. 367. Flower images D and H resemble Dendrobium ramossissmum sensu Lindley.
when forming a new subsection Ramosissima with a branching stem like D. ramosissimum"
(see below), cited only Wight leones t. 1648, (Reichenbach 1866). I have not seen the type
indicating D. ramossissimum as the only species. sheet, which is presumably in Reichenbach's
Hooker later, however, in his work on Indian or herbarium in Vienna. Seidenfaden has discussed
chids (1890), reduced D. ramossissimum to syn this species, with a drawing and flower photo
onymy with D. herbaceum. He did not refer to graph, in his treatment of Dendrobium in Thai
the possible third entity on the Lindley sheet. land (1985). Nunt (1999) has found it in several
The later authors listed above have followed parts of Myanmar.
him. Since World War II, native orchids have not Dendrobium parcum has long been exported
been widely exported from southern India, and from Thailand. I have grown and photographed
these plants are not in general cultivation over it. The lip is not constricted, and there are no
seas. side lobes. The blade gently expands distally,
Dendrobium parcum (meaning "scanty, mea with a squarish and slightly ecarinate tip. The
ger"), the second established species in section flowers are concolor dull yellow, the lip some
Herbacea, inhabits Myanmar (Burma), Thai times variably speckled with purple. Seidenfad
land, and Vietnam, and presumably also inter en (1992) considered the Vietnamese D. parcoi
vening Cambodia and Laos. After the conquest des Guillaumin (1955) synonymous. At issue are
of Burma, the indefatigable Rev. C. S. P. Parish, only the lip markings, inconstant in both taxa.
British chaplain at Moulmein, found this species A fifth taxon in the section is D. listeroglossum
in the southern peninsular area called Tenasser Kraenzl. (1892), which the author later (Kran
im. The plant was flowered in England by Low zlin 1910) reduced to synonymy with D. par
& Co., who submitted it to H. G. Reichenbach cum.
for identification. Its name fits his comment in George Bentham and J. D. Hooker (1883), in
the description: "a very poor-looking specimen their reclassification of Dendrobium, created a
120 SELBYANA Volume 28(2) 2007
FIGURE 4. Dendrobium ramossissmum sensu Wight, detail from type specimen.
FIGURE 5. Dendrobium ramosissimum-Wight detail from type drawing.
WOOD: DENDROBIUM SECTION HERBACEA 121
FIGURE 6. Dendrobium ramosissimum [sic] Wight type drawing. "Dendrobium ramossissimum" sensu Lind
ley. Lindley's drawing of specimen Stocks 52.
subsection Ramosissimae within section Stach land (1985) and Indochina (1992) reluctantly
yobium. As noted above, in the description they followed Kriinzlin. He included D. parcum in a
named no species but referred to Wight Ie. t. broad section Pedilonum, suggesting (1985) that
1648, the citation for D. ramossissimum. Later it might be better placed "elsewhere."
Hooker (1890) grouped D. herbaceum and D. The species under discussion do not have the
parcum together as the only members of an un unbranched stem, long inflorescence, or clearly
named subgroup in section Stachyobium, with three-lobed and usually pointed lip with conical
D. ramossissimum a synonym of D. herbaceum. mentum which are characteristic of section
Kriinzlin (1910), in his monograph on the
Stachyobium. Nor do they have the unbranched
Dendrobiinae, created a section Herbacea in
stem, condensed raceme, simple ovoid lip, or
Dendrobium, within a subgenus Eudendrobium,
long straight mentum of section Pedilonum. In
specifying a lip with side lobes (borderline cor
her review of the latter section, Dauncey (2003)
rect for D. herbaceum, incorrect for D. parcum).
omits them.
He included along with D. herbaceum 4 other
Thus, these humble but intriguing plants re
species, 3 of which correctly belong in other
quire their own section, which assumes the ear
sections, and 1 which is nebulous. These are D.
liest applicable name at sectional level. Krtin
(Stachyobium) heyneanum Lindl., D. (Fytchian
zlin's Herbacea is the only possibility despite
the) graminifolium Wight, and poorly known D.
the faults of his protologue, lack of a type spe
miserum Rchb.f., all from Asia; and D. (Ma
crostachyum) polycladium Rchb.f. from New cies, and heterogeneity of the taxa originally in
Caledonia. Kranzlin placed D. parcum in anoth cluded. D. herbaceum Kraenzl., the only surviv
er subgenus, Pedilonum, for species lacking ing taxon from the original list and the one
sidelobes. whose name identifies the section, is the type
Section Herbacea has been ignored by sub species under the rules (Greuter et al. 1994).
sequent taxonomists. Pradhan (1979), in his sur Section Herbacea includes the following taxa:
vey of Indian orchids, generally followed Ben
tham and Hooker, placing D. herbaceum in a 1. Dendrobium herbaceum Lindl.
subgroup of a subsection of section Stachyob Synonym: D. ramossissimum Wight.
ium. Pradhan also assigned there the Indian 2. D. parcum Rchb. f.
members of section Fytchianthe Schltr. On the Synonyms: D. parcoides Guillaumin.
other hand, Seidenfaden in his works on Thai- D. listeroglossum Kraenzl.
122 SELBYANA Volume 28(2) 2007
3. Unnamed species (D. ramosissimum sensu Dauncey, E. 2003. A taxonomic revision of Dendro
Lind!., non Wight). bium section Pedilonum (Orchidaceae). Harvard
Papers in Botany 7(2): 151-320.
From the point of view of morphology, the Fischer, CE.C. 1928. Orchidaceae, v. 3. In J.S. Gam
affinities of section Herbacea are unclear. No ble, ed. Flora of the Presidency of Madras. Reprint
other Asian section closely resembles it. Its 1984.
Guillaumin. A. 1955. Dendrobium parcoides. Bull.
branching habit and primitive flower structure
Mus. Paris II, 27 (2): 142.
recall the tall-growing terrestrial section Macro
Hall, R. and J.D. HoJloway, eds. 1996. Biogeography
cladium of New Caledonia, which, however, has and Geological Evolution of SE Asia. Backhuys,
verrucose roots. DNA study by Yukawa (2001) Leiden.
places it sister to section Fytchianthe but not Hooker, J.D. 1890. Flora of British India 5: 719. Re
close to section Stachyobium, and far distant print 1973.
from section Macrocladium. Joseph, J. 1987. Orchids of Nilgiris. Botanical Survey
The members of section Herbacea in southern of India, Calcutta.
Krlinzlin, F. 1892. Dendrobium listeroglossum. Xen.
India and southeast Asia have evidently been
Orch. 3: 108 and t. 260.
separated by the intermittent development of
---. 1910. Orchidaceae-Monandrae-Dendrobi
aridity in the Indo-Gangetic Plain, subsequently
inae. In A. Engler. ed. Das Pflanzenreich 45: 1-
evolving into distinct species. Many other plant 382.
groups have a similar disjunct distribution. Kroenke, L. 1996. Plate tectonic development of the
western and southwestern Pacific: Mesozoic to the
present. Pp.19-34 in A. Keast and S.E. Miller.
ACKNOWLEDGMENTS eds. The Origin and Evolution of Pacific Island
Biotas, New Guinea to Eastern Polynesia: Patterns
I thank Elizabeth Dauncey and Jeffrey J. and Processes. SPB Academic Publishing, Am
Wood at the Royal Botanic Gardens, Kew, and sterdam.
A. E. Schuyler at the Academy of Natural Sci Lindley, J. 1840. Dendrobium herbaceum. Bot. Reg.
ences of Philadelphia, for help with this paper. I 26: Misc. 69.
also appreciate permission to examine, photo ---. 1859. Contributions to the orchidology of In
graph, and publish images of specimens in the dia n. Proc. Linn. Soc. (Botany) 3: 1-63.
Nunt, Kyaw. 1999. Dendrobiums of Myanmar. Pp. 85-
Lindley Herbarium and Wight Herbarium at the
99 in Proc. 6th Asia Pacific Orchid Conf. Towns
Royal Botanic Gardens, Kew. I thank G. Sree
ville. Townsville Orchid Society, Australia.
kandan Nair, Director of the Tropical Garden Pradhan, U. 1979. Indian Orchids: Guide to Identifi
and Research Institute, Palode, Kerala, India, for cation and Culture, Vol. 2. Published by author,
permission to reproduce Figure 3. Kalimpong, India.
Reichenbach. H.G. 1866. Dendrobium parcum. Gard.
Chron. 1866: 1042.
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