Taxonomic treatment
Geodorum laxiflorum Griff., Calcutta J. Nat. Hist. 5: 356, t. 24.
1845; Hook. f., Fl. Brit. India 6: 18. 1890; Seidenf., Opera Bot. 72:
51. 1983; S. Misra, Orch. Orissa: 560. 2004; Misra, Orch. Orissa Handb.:
180. 2014; M.R. Bhatt et al. Richardiana 15: 335. 2015; Veeranjaneyulu
et al. Res. Ex. Inter. Multidis. Res. J. 7(7): 38. 2017; A.R. Bhoyar &
al., J. Threat. Taxa 14(2): 20689. 2022 – Lectotype (designated
here): INDIA. ‘HBC’, Griffith s.n. (CAL barcode
CAL0000055002!, Fig. 2a; collector’s name not mentioned on label, but
identified with handwriting).
Syntype. – Assam, Jenkins s.n. (CAL barcode
CAL0000086400!, Fig. 2b).
≡ Eulophia diffusiflora M.W. Chase, Kumar & Schuit., Phytotaxa
49(1): 52. 2021, syn. nov.
Description. – Terrestrial herbs, 20–40 cm long or
rarely up to 50 cm. Corms or pseudobulbs 2–4 cm long, 1–2 cm thick,
oblique, ovoid, slightly compressed, greenish brown, with scars of
fallen leaves, borne on a short rhizome. Roots few to many, 2–12 cm
long, vermiform. Pseudostem 6–10 cm long, enclosed by 3–4 foliar
imbricating sheaths. Leaves 2–5, arising from the basal node of tuber,
alternate, lamina ovate-lanceolate to elliptic-lanceolate, 12–36 ×
2.5–12 cm, entire, undulate, acute to subacuminate at apex, plicate,
many-veined, with long petiolar sheathing base. Inflorescence 14–27 cm
long, not exceeding the leaves, lateral, arising from the base of newly
developed pseudobulbs; peduncle 11–24 cm long, erect, terete, bearing
3–4 tubular sheaths; sheaths oblong, acuminate at apex, greenish,
membranous; rachis 2.5–3 cm long, mostly decurved towards the apex,
laxly 6–14 flowered with 2 sterile bracts. Floral bracts oblong to
lanceolate, 5–13 × 1.5–2 mm, shorter than pedicel plus ovary,
sometimes longer, entire, acuminate at apex, membranous, green,
obscurely 3-veined, externally pubescent; pedicel with ovary clavate,
5–10 mm long, green, ridged. Flowers 2–3 cm across, spreading, white,
labellum with yellow disc near middle and purplish tinge at apex. Sepals
subequal, oblong or oblong-lanceolate, entire, acute, 3–5-veined;
dorsal sepal 1.3–2.2 × 0.6–0.7 cm; lateral sepals 1.4–2.4 × 0.7–0.8
cm, often oblique at base. Petals elliptic-obovate to oblong-obovate,
broader than sepals, 1.4–2.3 × 0.7–1.2 cm, entire, obtuse at apex,
weakly oblique at base, 5-veined. Labellum cymbiform, broadly
ovate-cordate while spreading, 1.4–2 × 1–1.7 cm, sessile, ventricose
at base, sac pointing backward, margin entire, undulate with erect
lateral edges, slightly deflexed and emarginate at apex; disc pale to
bright yellowish, often slightly padded, purplish towards apex, base
with purplish-brown to creamy white to white short cellular hairs.
Column oblong, 5–7 mm long, stout, hairy at base, slightly dilated
above; stigma 1-lobed, ovate to dumbbell-shaped, slightly constricted at
middle; clinandrium shallow, keeled inside; anther 2-loculed, broadly
ovate-orbicular to orbicular-elliptic, 1.5–2.4 × 1.5–3 mm, locules
pouch like, white with purplish tinge; pollinia 2, oblong–ovoid, c. 2 ×
1.2 mm, deeply porate behind, yellow; caudicles hyaline, 1–1.2 mm long,
subquadrate, dilated above; viscidium ovate, 0.4–0.7 mm long, toothed
on both side, light yellowish-brown. Capsule 3–4.5 cm long,
oblong-ellipsoidal, 6-ridged, drooping.
Flowering & Fruiting. – May–September.
Habitat. – In tropical moist deciduous open forests up to 1200 m
elevation.
Distribution. – INDIA: Assam, Andhra Pradesh, Chhattisgarh,
Gujarat, Jharkhand, Maharashtra, Mizoram (reported here), Odisha,
Telangana, West Bengal (reported here); endemic.
Specimens examined. – INDIA: Assam, Jenkins s.n. (CAL,
syntype of G. laxiflorum ). Mizoram, Hualtu Range, Tawi Wildlife
Sanctuary, 13.03.2021 (flowered at rooftop plant conservatory of CAL on
24.06.2022), S. Sarkar & S. Chakraborty 41667 (CAL). West
Bengal, Howrah district, Acharya Jagadish Chandra Bose Indian Botanic
Garden (‘HBC’, in cultivation), Griffith s.n. (CAL, lectotype ofG. laxiflorum ); Paschim Bardhaman district, Garh Jungle,
08.06.2022, S. Mondal 3614A, 3614B (CAL).
Notes. – Geodorum laxiflorum is highly variable species.
The most significant variation is in the relative length of the floral
bract with respect to pedicel plus ovary. Griffith (1845), Bhatt et al.
(2015), Veeranjaneyulu et al. (2017), Bhoyar et al. (2022) described/
illustrated bracts which were shorter than the pedicel plus ovary.
During our study we have observed two kinds of bracts, even in the
plants of same subpopulation – i) shorter than the pedicel plus ovary,
and ii) longer than the pedicel plus ovary. The length of the bracts
varies from 0.5 to 1.3 cm. The shape and size of anther are also
significantly variable as the shape is broadly ovate-orbicular to
orbicular-elliptic. The size of broadly ovate-orbicular anthers varies
from 1.5–2 mm in length and 1.5–1.7 mm in breath, whereas the size of
orbicular-elliptic anthers is from 2–2.4 mm in length and 2.7–3 mm in
breath. The other variable characters in the species are length of the
plants, colour of labellum, shape and size of sepals and petals, size of
pollinarium, shape and size of pollinia (Figure 1).
In the protologue of G. laxiflorum , Griffith (1845) described the
labellum with a patch of purplish, short cellular hairs on the adaxial
surface near the base. These hairs are too tiny to be seen properly even
with modern dissecting stereo microscope and thus, this character has
not been described by the subsequent workers (Seidenfaden 1983; Misra
2004; Misra 2014; Bhatt et al. 2015; Veeranjaneyulu et al. 2017; Bhoyar
et al. 2022). During our study we observed not only the microscopic
cellular hairs near the base of labellum, but also variation in their
colour, which range from purplish to purplish-brown to creamy white to
white (Figure 1 k1, k2).
Geodorum laxiflorum was first described by William Griffith
(Griffith, 1845) based on Major Jenkins’s collection from Assam, which
flowered in the then Calcutta Botanic Garden (now Acharya Jagadish
Chandra Bose Indian Botanic Garden, Howrah) in the month of May.
Seidenfaden (1983) doubted the existence of any original material,
except a “fine drawing by Griffith at K”. Misra (2004) followed
Seidenfaden (1983) and mentioned the same in his work, though he did not
see the Griffith’s K-drawing. Bhatt et al. (2015) designated Griffith’s
drawing at K as lectotype of Geodorum laxiflorum . However, Bhatt
et al. (2015) did not see the K-drawing which was evident from their
citation of the lectotype. Dr Harry Smith, Curator-Botanist, Asia Team,
Science Collections, Herbarium, Royal Botanic Gardens, Kew, sent us
digital image of the only illustration of this species present at K and
mentioned (pers. comm., 12.07.2022) – “the information on the sheet
does not unequivocally suggest that it is indeed a drawing by
Griffith”. We are also in same opinion that the K-drawing (K001535002,
Figure 3) was not drawn by Griffith, but it is a copy from the original
drawing drawn by M.C. Noble in 1889 and therefore, it is not an original
material of G. laxiflorum as it postdates the publication of the
name. Dr Henry Noltie, Royal Botanic Garden, Edinburgh, informed (pers.
comm., 13.10.2022) that the K-drawing is undoubtedly an exact copy of
the original Griffith’s drawing of CAL. In the 1880s there was a
reciprocal exchange, i.e. drawings at CAL were copied for K and drawings
at K were copied for CAL, especially of orchids. Dr Noltie also added
“The name of the copy-artist is M.C. Noble, but I haven’t come across
this name and don’t know if he/she did the copying at CAL (most likely)
or whether the drawings were sent to Kew, copied by an artist there, and
then returned to CAL”. The writing ‘Ic Herb Calcutta’ by J.D. Hooker
and the writing ‘by M.C. Noble 1889’ on the K-drawing also confirms that
the K-drawing was copied from Griffith’s original drawing at CAL. Though
we did not found Griffith’s original drawing at CAL in spite of thorough
search, we found one of the unnoticed type-specimens of G.
laxiflorum at CAL (CAL0000086400, Figure 2b) which was collected by
Jenkins from Assam and was mixed with other Orchid-specimens at the
general herbarium of CAL. Though the flowers of the CAL-specimen are in
bud condition, but undoubtedly it is one of the original materials ofG. laxiflorum . Griffith (1845) mentioned that Jenkins’s collected
plants from Assam flowered later in May, and thus it is natural that the
CAL-specimen was in bud condition when mounted. While describingG. laxiflorum , Griffith (1845) compared it with G.
dilatatum R. Br. [= Geodorum recurvum (Roxb.) Alston] and
distinguished it from G. dilatatum in having thinly flowered
spike, broad petals, and the round cochleariform entire labellum, which
when spread out is of a cordate shape. Geodorum laxiflorumis also morphologically similar to G. densiflorum (Lam.) Schltr.,
but can be readily distinguished from the later in having much shorter
inflorescence, i.e. inflorescence not exceeding the leaves, absence of
longitudinal, irregular, yellow to whitish callus on disc of labellum
(but often slightly padded), and the labellum lacking crimson-purple
venation and streaks below the disc. In G. densiflorum the
inflorescence usually exceeds the leaves, the disc of labellum with low
but prominent, longitudinal, irregular (2-many dentate), yellow to
whitish callus, and the labellum with crimson-purple venation and
streaks below the disc. Further, the inflorescence of G.
laxiflorum is often comparatively less flowered, lax and flowers are
more open than that of G. densiflorum . We have traced out another
interesting specimen at CAL (CAL0000055002, Figure 2a) with Griffith’s
annotation (‘HBC’, i.e. Hortus Botanicus Calcuttensis) which was
identified by Griffith as ‘Geodorum laxiflorum ’. This
CAL-specimen is also with an inflorescence not exceeding the leaves and
moreover, the flowers are much open and in completely blooming
condition. This specimen also belongs to one of the original materials
of G. laxiflorum as Griffith (1845) mentioned that Jenkins’s
Assam-plants flowered in the Calcutta Botanic Garden. However, the other
data written on the herbarium-label are not readable due to the damage
of the label in the lower part, and due to unreadability of the date/
month/ year of collection. In December 1844 Griffith sailed for Malacca
from India for the second time and could not return to India as he was
seized with a fatal illness and died on 9 February 1845 in Malacca.
Therefore, it is obvious that this CAL-specimen (CAL0000055002)
annotated by Griffith predates the publication of G. laxiflorumand part of the original material of the name. Interestingly, this
CAL-specimen (CAL0000055002) is very much matching with the K-drawing ofG. laxiflorum (especially with respect to two apical leaves,
inflorescence and flowers) which was copied from Griffith’s original
drawing at CAL (presently not traceable). The other existing original
material of the name is the illustration [Icon Griffith
(Geodorum laxiflorum ) , Calcutta J. Nat. Hist. 5: Pl.
XXIV, tt. 1–7. 1845] published by Griffith (1845) in the protologue.
Among the all available original materials of G. laxiflorum , the
CAL-specimen ‘CAL0000055002’ is the most suitable choice for
lectotypification as the diagnostic characters of G. laxiflorumare more evident in this specimen. Hence, we are superseding the
lectotypification by Bhatt et al. (2015) in accordance with Art. 9.19 of
the ICN (Turland et al. 2018) and designating the CAL-specimen
(CAL0000055002) as lectotype of G. laxiflorum according to Art.
9.3, 9.12 of the ICN (Turland et al. 2018) as it has precedence over the
illustration published in the protologue. It is worth mentioning
that another name under the genus, viz. G. rariflorum Lindl. [=G. densiflorum (Lam.) Schltr.], was also based on Jenkins’s
collection from Assam, i.e. specimen with same label-data (‘Assam,
Jenkins’). However, the types of G. laxiflorum (CAL!) and ofG. densiflorum (K!) are taxonomically different.
Chase et al. (2021a) recently reduced Geodorum underEulophia R. Br. based on phylogenetic study and subsequently
proposed (Chase et al., 2021b) to conserve Eulophia overGeodorum. Chase et al. (2021a) treated Geodorum
laxiflorum Griff. under Eulophia as E. diffusiflora M.W.
Chase, Kumar & Schuit. (replacement name). However, treatingEulophia as a conserved name over Geodorum is subject to
acceptance the proposal in the XX International Botanical Congress to be
held in Madrid, Spain in 2024 and therefore, Geodorum must be
treated as correct name at present due to priority. Hence, E.
diffusiflora M. W. Chase, Kumar & Schuit. is treated here as a
homotypic synonym of G. laxiflorum Griff. until Eulophiais conserved against Geodorum .