Upload
francois-mey
View
221
Download
0
Embed Size (px)
Citation preview
8/3/2019 Cardamom Mountains Nepenthes Description
1/14
New Nepenthes
102
New
Nepenthes
Volume One
Pages from:
Published by
Redfern Natural History Productionswww.redfernnaturalhistory.com
New Nepenthes Volume One
Never have so many new tropical pitcher plants (Nepenthes) beendiscovered as during the three years since the publication of the first
complete monograph of the genus in 2009.Among them are eighteen new species,two revised species, one new variety,and two new but incompletely diagnosedtaxa from across Borneo, Indochina, NewGuinea, the Philippines and Sulawesi. Thenewly discovered plants include many oflargest, most extraordinary and colourful
carnivorous plants ever found. This workdocuments and depicts all of the newNepenthes in spectacular detail, and inmany cases for the very first time.
8/3/2019 Cardamom Mountains Nepenthes Description
2/14
New Discoveries in Indochina
103
New Nepenthes Volume One documents the following taxa,along with many other spectacular new pitcher plants....
Redfern Natural History Productionswww.redfernnaturalhistory.com
Nepenthes hamiguitanensis Nepenthes lamii Nepenthes leonardoi
Nepenthes appendiculata Nepenthes ceciliae Nepenthes epiphytica
Nepenthes nigra Nepenthes pulchra Nepenthes thorelii
8/3/2019 Cardamom Mountains Nepenthes Description
3/14
8/3/2019 Cardamom Mountains Nepenthes Description
4/14
New Discoveries in Indochina
151
Figure 115 (above). An unusual sub-
globose lower pitcher found in two
isolated plants in nearby forest.
Figure 116 (above). The elongate
pitchers of the Cardamom Mountains veal
Nepenthes.
Figure 117 (above).The pale colour of
a newly opened pitcher produced by the
Cardamom Mountains veal Nepenthes.
Figure 118 (above). A Cardamom
Mountains veal Nepenthes upper pitcher,
flushed an attractive shade of hot pink.
8/3/2019 Cardamom Mountains Nepenthes Description
5/14
New Nepenthes
152
Samkos Wildlife Sanctuary, part of the poorly surveyed CardamomMountains region of southwest Cambodia. The aim of the expedition
was to survey for large mammals. The proposed survey area was a seriesof mountainous ridges and grassland plateaus extending from PhnomSamkos, Cambodias second highest mountain at 1717 m, to the finalescarpment that overlooks Thailand to the southwest. The habitat in thisregion ranges from 8001500 m and is composed of tropical evergreenforest interspersed with open, grassy veals. Despite almost a decadeof research carried out in the Greater Cardamoms, this area had neverbefore been visited by researchers, and rarely, if ever, by local people. Alegacy of two decades of fighting in the Cardamoms has left the regiondotted with landmines, placed by Khmer Rouge soldiers, the governmentforces opposing them, and by the Vietnamese army. As a consequence,there is no clear idea where all the mines are placed and certain areasremain dangerous to visit (Brocheux & Hemery, 2004). Minefields inthe forests surrounding Thma Da village make access into the proposedsurvey area difficult from the southern lowlands from where it might
be more easily reached. The only remaining route is by passing over theGreater Cardamom Mountains, a much harder alternative, but one thatis, at least, free from mines. The target area for the survey was a series ofveals traversing west to east along the most southern escarpment. Theseveal areas were identified from maps and reached after five days on foot,following a direct compass bearing across the mountains.
Previous interviews with villagers had suggested that Nepenthesdid not occur on these high veals. However, extensive populations ofNepenthes kampotiana Lecomte are known to grow in veals in Koh Kongprovince between 100600 m, sometimes along the road; while Nepenthesmirabilis (Lour.) Druce occurs in the marshlands around Veal Veng (550 m)in OSom to the east (pers observ.). Local people knew about Nepenthespopulations in OSom, but claimed that they did not occur at higherelevations. It was therefore a surprise to emerge from the dense montane
scrub forest on one peak to discover a veal covered in Nepenthes plants thatformed vast, contiguous carpets. Without permits to do so, no voucherspecimens of this taxon were collected. It seemed clear, however, that
Figure 119 (facing page). An isolated Cardamom Mountains veal Nepenthes growing
beneath a pine tree in an open area.
8/3/2019 Cardamom Mountains Nepenthes Description
6/14
New Discoveries in Indochina
153
8/3/2019 Cardamom Mountains Nepenthes Description
7/14
New Nepenthes
154
given the overall similarity of these plants to other Indochinese species,they fit into what is referred to as the N. thorelii aggregate (Mey et al.,
2010). Even so, the specific identity of these plants remains uncertainin the absence of further investigation. This plant was first introduced asan unidentified Nepenthes taxon from Cambodia in a recent publication(McPherson, 2009). A few hundred metres from the large colonies,two different, isolated plants were observed; these developed reddishsub-globose pitchers (Figure 115) and were both found in the densemontane forest surrounding the veal.
Key features of this taxon show that it is very closely related tothe other pyrophytic Nepenthes; the leaf base is sub-petiolate, claspingthe stem and decurrent; the lower pitchers are often red, ovate at thebase and cylindrical above, while the upper pitchers are pale yellow,sometimes suffused with red, narrowly cylindrical and slightly swollenin the lower third, to narrowly infundibular (Figures 116, 117, 118 and119); there is no appendage underneath the lid; the inflorescence is
racemose with flowers borne solitarily on pedicels that may develop abasal bract. These features match the superficial morphology of several ofthe N. thorelii aggregate taxa, in particular N. smilesii Hemsl., with which itfollows both morphological and ecological similarities. Nepenthes smilesiiis the most widespread species of the aggregate and has been observed atsimilar elevations on Mount Lang Bian, near Dalat, Vietnam, on MountSt (Phu St) in southern Laos, and on Mount Kradung (Phu Kradung)in Thailand (observations from collections deposited in Paris MNHNherbarium (P)). However, the leaves of this Cardamom taxon, whichare lanceolate, seem to be shorter than those ofN. smilesii or indeed ofany of the other species in the N. thorelii aggregate. This feature might bedue to the high light levels that these plants must experience, growing inan elevated and completely open habitat. Another species known fromthe Cardamom Mountains, Nepenthes holdenii Mey, cannot be confusedwith this unidentified taxon because of their different morphology and
ecology: N. holdenii develops a different inflorescence structure as wellas different upper pitchers, and is found in the transitional zone (600800 m) between lowland evergreen forest and low montane evergreenforest on steep ridges in bright to fully sun-exposed areas, often inassociation with Pinus species.
8/3/2019 Cardamom Mountains Nepenthes Description
8/14
New Discoveries in Indochina
155
This taxon appears to favour open grassland and was not seen onthe low bushes on the veals or the surrounding trees, in contrast with N.
kampotiana populations occurring in the neighbouring lowlands. A fewhundred metres from the large colonies, two different, isolated plants wererecorded: these developed reddish sub-globose pitchers and were bothfound in the dense montane forest surrounding the veal, growing as slendervines. The vines were gracile, with extremely long tendrils compared toany of the other known Indochinese taxon. It is likely that these two plantswere ecotypes: N. bokorensis Mey, a Cambodian endemic, has also recentlybeen found growing in such conditions and develops similarly long tendrilsin Mount Bokors montane forest (Mey & Robinson, pers. observ., 2011).
The most unusual and striking feature of this population was theextensive carpets formed by the plants (Figures 120 and 121). Althoughclearly not a closely related species, these carpets are reminiscent of thedense populations of Nepenthes madagascariensis Poir. (Figure 122) seenin the lowlands of Madagascar. It is as yet unknown why this Cardamom
taxon develops such extensive carpets (Figures 123 and 124). The remoteposition of these veals puts them far from human habitation, and perhapsbecause of this they experience fewer fires than similar habitats in closerproximity to villages. Although there was some evidence that pigs wererooting up the Nepenthes tubers, there was no sign of larger ungulates suchas gaur (Bos frontalis) visiting these veals. It was also clear from the numberof large orchids growing in the vicinity that plant collectors had not visitedthe area. In the absence of potential disruptions, such as regular fires,trampling from large mammals that could possibly damage the pitchers,and collection by humans, these plants have possibly been given the chanceto grow unimpeded over the years to form these unusually large carpets.
Acknowledgements: The authors would like to thank CambodiasMinistry of Environment for permission to visit the Phnom SamkosWildlife Sanctuary and other areas under their jurisdiction, and Fauna &
Flora International and the Royal University of Phnom Penh for supportingthe expedition. We are thoroughly grateful to Dr Neil Furey and to IthSaveng, who acted as an exemplary counterpart, translator and map-reader,and to pitcher plants enthusiast, Jacques Besnard, for his beautiful habitatphotograph ofNepenthes madagascariensis.
8/3/2019 Cardamom Mountains Nepenthes Description
9/14
New Nepenthes
156
8/3/2019 Cardamom Mountains Nepenthes Description
10/14
New Discoveries in Indochina
157
Figure 122 (above).The growth habit of the Cardamom Mountains veal Nepenthes is
reminiscent ofNepenthes madagascariensis, a distantly related taxon.
Figures 123 (pages 158 and 159) 124 (pages 160 and 161). The Cardamom
Mountains veal Nepenthes in situ, forming massed carpets of pitchers across the ground.
Figure 120 (facing page). The proximity of the underlying rock stratum is largely
responsible for the open aspect of these veals.
Figure 121 (above). The pale upper pitchers of the Cardamom Mountains veal
Nepenthes contrast strongly with the darker surrounding vegetation.
8/3/2019 Cardamom Mountains Nepenthes Description
11/14
New Nepenthes
158
8/3/2019 Cardamom Mountains Nepenthes Description
12/14
New Discoveries in Indochina
159
8/3/2019 Cardamom Mountains Nepenthes Description
13/14
New Nepenthes
160
8/3/2019 Cardamom Mountains Nepenthes Description
14/14
New Discoveries in Indochina
161