Journal of Threatened Taxa | www.threatenedtaxa.org | 26 September 2019 | 11(12): 14518–14526

 

 

Seasonal vegetation shift and wetland dynamics in vulnerable granitic rocky outcrops of Palghat Gap of southern Western Ghats, Kerala, India

 

Pathiyil Arabhi 1  & Maya Chandrasekharan Nair 2

 

1 Environmental Resources Research Centre (ERRC), NCC Road, P.B. No. 1230, P.O. Peroorkada, Thiruvananthapuram, Kerala 695005, India.

1 Department of Botany, Baselius College, K.K. Road, Kottayam, Kerala 686001, India.

2 Post Graduate and Research Department of Botany, Govt. Victoria College (University of Calicut), College Road, Palakkad, Kerala 678001, India.

1 arabhip1@gmail.com (corresponding author), 2 drmayadhoni@gmail.com

 

 

 

Abstract: Low altitude granitic hillock systems prevalent in Palghat (Palakkad) Gap region of southern Western Ghats were analyzed for seasonal dynamics in wetland taxa associated with marshy ephemeral flush vegetation, small ephemeral pools and deep rock pools.  Due to characteristic habitat features, such systems harbor a unique pattern of microhabitats and associated floristic components.  Wet phase in rocky outcrops in the monsoon season establishes a hydro-geomorphic habitat that supports establishment of wetland taxa like Eriocaulon, Drosera, Utricularia, Dopatrium, and Rotala.  Seasonal shift in the floral associations was evident in tune with wetland dynamics.  Wet rocks support ephemeral flush vegetation which display some unique plant associations of species of Eriocaulon, Utricularia, Drosera, Cyanotis, Murdannia, and Lindernia.  Small ephemeral pools displayed taxa like Rotala malampuzhensis R.V. Nair, Dopatrium junceum (Roxb.) Buch.-Ham. ex Benth., D. nudicaule (Willd.) Benth., Monochoria vaginalis (Burm.f.) C. Presl, and Cyperus iria L.  Rocky pools are the habitats of aquatic angiosperms like Nymphaea nouchali Burm. f., Ludwigia adscendens (L.) H. Hara, Utricularia aurea Lour. and Hydrilla verticillata (L.f.) Royle.  The study documented 121 plant taxa from 37 families during a wet phase from rocky outcrops of the study area.  Gradual shift in vegetation is evident as water recedes from granitic hillocks.  During the period from December to March, the rocky pools dry up which results in a shift in the vegetation pattern where Poaceae members form the dominant elements.  As most of the rocky outcrops are exposed to extreme temperature and acute water shortage, the taxa inhabiting such ecosystems tend to evolve much faster than in other habitats.  Moreover, the vicinity of these hillocks in the Palghat Gap region to human settlements, face threats like fire, grazing, quarrying, dumping of wastes etc. which may cause considerable loss to the very sensitive plant communities which are not yet fully documented.

 

Keywords: Granitic hillocks, Palakkad, vegetation shift, wetland dynamics.

 

 

 

doi: https://doi.org/10.11609/jott.4732.11.12.14518-14526   

 

Editor: Vijayasankar Raman, University of Mississippi, Mississippi, USA.         Date of publication: 26 September 2019 (online & print)

 

Manuscript details: #4732 | Received 27 November 2018 | Final received 01 July 2019 | Finally accepted 01 September 2019

 

Citation: Arabhi, P. & M.C. Nair (2019). Seasonal vegetation shift and wetland dynamics in vulnerable granitic rocky outcrops of Palghat Gap of southern Western Ghats, Kerala, India. Journal of Threatened Taxa 11(12): 14518–14526. https://doi.org/10.11609/jott.3891.11.12.14518-14526

 

Copyright: © Arabhi & Nair 2019. Creative Commons Attribution 4.0 International License.  JoTT allows unrestricted use, reproduction, and distribution of this article in any medium by adequate credit to the author(s) and the source of publication.

 

Funding: None.

 

Competing interests: The authors declare no competing interests.

 

Author details: Pathiyil Arabhi is working as Assistant Professor in Department of Botany, Baselius College, Kottayam. Dr. Maya Chandrasekharan Nair is Assistant Professor and Head, Post Graduate and Research Department of Botany, Govt. Victoria College, Palakkad who is specialized in plant taxonomy and floristics.

 

Author contribution: Both the authors contributed equally in preparation and compilation of the manuscript.

 

Acknowledgements: First author is thankful to Director, and staff of Environmental Resources Research Centre (ERRC), Thiruvananthapuram and Principal, Baselius College, Kottayam for the support and encouragement. The second author acknowledges the support from Director, Collegiate Education, Govt. of Kerala and Principal, Govt. Victoria College, Palakkad for the facilities and encouragement.

 

 

 

Introduction

 

Rocky outcrops, which rise abruptly from the surrounding landscape, have a patchy distribution, and represent centers of diversity and endemism for both animal and plant life (Hopper & Withers 1997).  They support high levels of species diversity and endemism, have provided stable micro-climates for thousands of years and also provide important insights into our ecological past where they contain the remains of extinct species (Fitzsimons & Michael 2017).  They exhibit extreme climatic and edaphic features strikingly different from the surrounding environment.

The Palghat Gap, a 32-km break in the hill ranges of the Western Ghats with an average elevation of 140m, is a peculiar geological feature in southern India along 10.7500N latitude which divides the Western Ghats into Nilgiri Hills on the northern lip and Anamalai-Palani Hills on the southern lip.  The gap area is characterized with gneissic, charnockite and amphibolite rock types (Cruz et al. 2000).  Small and medium-sized rocky hillocks are common in the Gap area and most of them are covered with rich vegetation providing rich grazing areas for cattle.  They perform significant ecosystem services, as the main repositories of water resources keeping the wells of nearby areas filled.  In Kerala, lateritic and granitic hillocks occur with a prevalence of lateritic ones in northern and granitic hillocks in southern Kerala.  Numerous low-altitude hillock systems which are characteristic to the Palghat Gap region of southern Western Ghats have their own unique manifestations of floral elements due to spatial and ecological isolation from the surrounding vegetation.  These granitic outcrops provide suitable microhabitats for many rare and endemic plants.  Floristic explorations on such low-altitude hillocks resulted in the discoveries of taxa new to science (Jose et al. 2013, 2015).

Low-altitude hillock systems exhibit seasonal wetland dynamics and periodical shifts in vegetation patterns in response to the onset and retreat of the monsoons.  The wet phase in such hillock systems is characterized by unique associations of ephemeral herbaceous floral elements in specific microhabitats like seasonal pools (Pramod et al. 2014).  Most of the hillocks in the Palghat Gap region are found in the neighborhood of human settlements and are facing various threats, including fire, grazing, quarrying and dumping of wastes, which cause considerable loss to the very sensitive plant communities which are not yet fully documented.  With this background, the present paper summarizes the floristic diversity of ephemerals associated with the microhabitats of granitic hillocks in the Palghat Gap of southern Western Ghats.

 

 

Materials and Methods

 

Study Area

Documentation of wetland taxa in selected granitic hillocks of seven different forest ranges, viz., Alathur, Kollengode, Nelliyampathy, Olavakkode, Ottappalam, Walayar, and Mannarkkad was carried out between June 2016 and May 2018.  The sampling locations lie between 10.551–11.010 0N and 76.161–76.828 0E (Image 1).  The plants were collected and identified using regional floras along with reference to local herbaria MH and CALI and enumerated based on APG IV (Chase et al. 2016).  The nomenclature validation was carried out using IPNI (www.ipni.org), The Plant List (www.theplantlist.org) databases and Flowering Plants of Kerala (Sasidharan 2014).  The plant diversity in different microhabitats during the wet phase were identified (Sreejith et al. 2016), documented and seasonal vegetation shift was observed.  The threat assessment of the taxa was based on IUCN (2019) guidelines.  The plants and habitats were photographed using digital cameras Nikon D 3200 and Sony Cyber shot DSC HX7V.

 

 

Results and Discussion

 

Granitic hillock systems harbor unique microhabitats and associated floristic components.  Seasonal shift in vegetation was apparent, which shows demarcating wet and dry phases based on the availability of moisture.  The micro environment on the rock surface in these hillock systems varied between extremely hot and arid in dry seasons to water logged and slippery in the wet season.  Microhabitat conditions present on the outcrops vary significantly from the adjoining areas and hence they can be referred to as terrestrial habitat islands.

 

Wet phase in granitic hillocks

 The establishment of the wet phase in the rocky outcrops begins with the onset of the southwest monsoon and ends with the completion of the northeast monsoon.  Occurrence of the wet phase in rocky outcrops in the form of different microhabitats in the monsoon season (June–November) establishes hydro-geomorphic habitats with significant microhabitats and floral associations (Image 2).

Ephemeral flush vegetation (EFV): This is the predominant vegetation type occurring in the microhabitats of granitic hillocks during the wet phase.  The ephemeral herbaceous plants flourish in the open rocky slopes through which water flows slowly.  This microhabitat harbors 11 species, viz., Burmannia coelestis D. Don, Cyanotis papilionacea (Burm. f.) Schult. & Schult. f., Drosera indica L., D. burmanni Vahl, Eriocaulon pectinatum Ruhland, E. thwaitesii Körn., E. xeranthemum Mart., Lindernia ciliata (Colsm.) Pennell, Murdannia semiteres (Dalzell) Santapau, Utricularia lazulina P. Taylor, and U. graminifolia Vahl; and of these, species of Utricularia are exclusive EFV endemics and the insectivorous taxa which prefer nutrient deficient soil, viz., Drosera spp. and Utricularia spp., were found to be well adapted to this habitat.  This micro-eco-climate showed unique plant associations between Eriocaulon-Utricularia-Drosera and Lindernia.

Small ephemeral pools (SEP): Most of the rocky outcrops possess several shallow depressions which remain filled with water during the rainy season.  They form unique microhabitats for some wet phase elements, such as, Dopatrium junceum (Roxb.) Buch.-Ham. ex Benth., D. nudicaule (Willd.) Benth., Rotala indica (Willd.) Koehne, R. malampuzhensis R. V. Nair, Monochoria vaginalis (Burm. f.) C. Presl, and Cyperus iria L.  The study recorded 20 species (Table 1) from this microhabitat and the above six taxa were specifically confined to this microhabitat.

Rock pools (RP): Some hillocks possess deep water-filled pools mainly created as a result of quarrying which harbor aquatic taxa like Nymphaea nouchali Burm.f., Hydrilla verticillata (L.f.) Royle, Ludwigia adscendens (L.) H. Hara, Utricularia aurea Lour., Ipomoea aquatica Forssk., Marsilea quadrifolia L., and Rotala mexicana Schltdl. & Cham.  This unique ecosystem recorded eight species, of which the first four members were recorded from this microhabitat only.

Exposed rock surfaces (ERS):  These are flat or irregular rocky surfaces which were directly exposed to sunlight.  These areas with poor soil deposition remain more or less wet during the rainy season.  This survey recorded 35 taxa from this microhabitat, viz., Burmannia coelestis D.Don, Centranthera indica (L.) Gamble, Geissaspis cristata Wight & Arn., and Lobelia alsinoides Lam., of which Xyris pauciflora Willd. was recorded specifically from this microhabitat.

Rocky crevices and fissures (RCF): Granitic outcrops possess several rock crevices and fissures with very thin soil deposition which act as ecological niche for some specific species like Henckelia incana (Vahl) Spreng. and Cyanotis arachnoidea C.B. Clarke, and about 14 species were recorded from this microhabitat and the above mentioned taxa were specifically confined to this habitat.

Soil-filled depressions (SFD): Rocky outcrops possess several depressions which accumulate water and soil during the rainy season and provide a marshy habitat.  Around 81 species were recorded from this particular microhabitat of which Alysicarpus monilifer (L.) DC., Isoetes coromandeliana L.f., Crotalaria linifolia L.f., Cyanotis burmanniana Wight, Ophioglossum nudicaule L.f., Lindernia anagallis (Burm.f.) Pennell, Ludwigia hyssopifolia (G.Don) Exell, Mitrasacme pygmaea R.Br., etc. were some species found exclusively in this microhabitat.

Soil rich area (SRA): These microhabitats with good soil deposition having more than 20cm soil thickness, during the wet phase were frequently occupied by species like Chrysopogon aciculatus (Retz.) Trin, Cyanotis cristata (L.) D.Don, Eclipta prostrata (L.) L., Spermacoce articularis L.f., Spermacoce hispida L., Spermacoce alata Aubl., Commelina clavata C.B. Clarke, Commelina diffusa Burm.f., Eragrostis unioloides (Retz.) Nees ex Steud., and Spermacoce ocymoides Burm.f.  Among them, the first six taxa were exclusively found in this microhabitat.

Boulders (B): These microhabitats consist of isolated rocks or large rocks in groups which were found to be inhabited with some mosses, pteridophytes like Cheilanthes opposita Kaulf., Parahemionitis cordata (Hook. & Grev.) Fraser-Jenk. and angiosperms like Bulbostylis barbata (Rottb.) C.B. Clarke, Osbeckia muralis Naudin, and Oxalis corniculata L. during the wet phase.

During the study 121 plant species belonging to 37 families (Table 1) were documented from different microhabitats in the wet phase (June–November).  The most represented family were Fabaceae with 22 species followed by Cyperaceae with 16 species and Commelinaceae with 10 species.

 

Dry phase in granitic hillocks

 A gradual shift in vegetation was evident as water receded from granitic hillocks after the retreat of the monsoon.  During the period from December to April, the small ephemeral pools dry up, ephemeral flush vegetation disappears, water level in deep rock pools lowers, which results in a shift in wet vegetation to a drought-adaptive taxa.  Dry phase is characterized by the complete absence of microhabitats like EFV and SEP and shift in plant associations in other microhabitats like ERS, RCF, SFD and SRA (Image 3).

 During the dry phase, plant species like Heliotropium marifolium J. Koenig ex Retz. and Cleome aspera J. Koenig ex DC. dominate in exposed rock surfaces (ERS) and rock crevices and fissures (RCF) harbors plant taxa like Anisochilus carnosus (L.f.) Wall., Andrographis echioides (L.) Nees, Cleome viscosa L., Dimeria deccanensis Bor, Hyptis suaveolens (L.) Poit., and Theriophonum fischeri Sivad.  Plant species like Perotis indica (L.) Kuntze, Croton hirtus L’Hér., Ischaemum rugosum Salisb., Rhynchosia rufescens (Willd.) DC., Blumea virens DC., Richardia scabra L., Tephrosia villosa (L.) Pers., Merremia tridentata (L.) Hallier f., and Apluda mutica L. were mostly seen in soil-filled depressions (SFD) during the dry phase.  Soil rich area (SRA) is dominated by plant taxa such as Alternanthera bettzickiana (Regel) G. Nicholson, Achyranthes aspera L., Acalypha alnifolia Klein ex Willd., Sesamum radiatum Schumach. & Thonn., Sida cordata (Burm.f.) Borss. Waalk., Boerhavia diffusa L., Ipomoea pes-tigridis L., grasses like Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult., Arundinella mesophylla Nees ex Steud., and Garnotia tenella (Arn. ex Miq.) Janowski during the dry phase.  During the dry phase, the mosses and pteridophytes inhabited on boulders (B) dry up.

Both dry and wet phases in granitic outcrops share floristic elements of scrub jungles and tree cover and such vegetation provides isolated patches of greenery to these vulnerable habitats.

 

Scrub jungle elements

Some shrubs and climbers give a stunted forest appearance to the rocky hillocks. Ziziphus jujuba Mill., Z. oenopolia (L.) Mill., Canthium coromandelicum (Burm.f.) Alston, C. rheedei DC., Euphorbia trigona Mill., Flacourtia indica (Burm.f.) Merr., Ehretia microphylla Lam., Catunaregam spinosa (Thunb.) Tirveng., Casearia esculenta Roxb., C. wynadensis Bedd., Abrus precatorius L., Getonia floribunda Roxb., Pterolobium hexapetalum (Roth) Santapau & Wagh, and Spatholobus parviflorus (DC.) Kuntze. are some of the common scrub jungle elements found in rocky systems.

 

 Tree cover

The extent of tree cover varies in different hillock systems from thick tree cover and associated shade loving shrub elements to hillock systems with sparsely distributed tree species.  This study documented 100 tree taxa from rocky hillocks and among them, Cochlospermum religiosum (L.) Alston, Givotia moluccana (L.) Sreem., Firmiana simplex (L.) W. Wight, Phyllanthus emblica L., Strychnos nux-vomica L., S. potatorum L.f., Morinda pubescens Sm., Azadirachta indica A. Juss., Holarrhena pubescens Wall. ex G. Don, Cleistanthus collinus (Roxb.) Benth. ex Hook.f., Wrightia tinctoria R.Br., Ficus exasperata Vahl, Pterocarpus marsupium Roxb., and Terminalia paniculata Roth. were common inhabitants of most of the rocky hillocks.

 

Threatened Taxa with conservation significance

The vulnerable habitats of granitic rocky outcrops of the Palghat Gap of the southern Western Ghats harbor taxa with conservation significance.  The analysis revealed the presence of five taxa under threatened category (IUCN 2019).  Pterocarpus marsupium Roxb. among tree cover element is classified as Near Threatened and Cleistanthus collinus (Roxb.) Benth. ex Hook.f. and Santalum album L. are Vulnerable.  The wet phase taxon, Eriocaulon pectinatum Ruhland and scrub jungle element, Casearia wynadensis Bedd. are also classified as Vulnerable as per IUCN Red List of Threatened Plants version 2019-2 (IUCN 2019).  Conservation status of about 45% wetland taxa recorded from the study area are not yet assessed and as the habitats of these elements are facing serious threats, the future of these taxa inhabiting these niche is uncertain.

 

Threats to low altitude hillocks in Palghat Gap region

Rapid urbanization places anthropogenic pressures on low altitude granitic hillocks in the Gap region of the southern Western Ghats.  Indiscriminate quarrying poses serious threats to the unique flora and fauna on the granitic hillocks.  Some of the low altitude hillocks on either side of the national highways were destroyed for expansion of the highway.  The hillocks near human settlements have become dumping grounds for disposal of wastes which adversely affects the soil quality and vegetation.  Invasion of Chromolaena odorata (L.) R.M. King & H. Rob. and Mimosa diplotricha Sauvalle and promotion of monoculture plantations of Tectona and Acacia were found to retard the growth of indigenous flora of the hillocks.  During the dry phase, most of the rocky outcrops were dominated by fire-indicating taxa like Hyptis suaveolens (L.) Poit. and grasses like Apluda mutica L. which easily catch fire and lead to the loss of natural vegetation.  Some of these hillocks are susceptible to landslides owing to indiscriminate quarrying which in turn destroy entire flora and fauna of associated microhabitats.

 

 

Conclusions

 

All microhabitat categorizations are limited by factors such as soil depth, water content and other seasonal variations and there is no clear physical demarcation between the habitats.  The onset of the monsoon season leads to dispersion of water in soil-filled depressions or even flat surfaces and hence overlay in species composition can be observed in these habitats.  While some taxa were restricted to a single microhabitat, other species were able to grow in an array of closely similar microhabitats although their dominance levels varied with reference to specific habitat inclinations and niche.

The documentation of taxa during the wet phase alone could record 121 elements belonging to 37 families distributed in eight different microhabitats which are ephemeral and seasonal.  The adaptive strategies provided by such microhabitats support taxa which have narrow ecological amplitude and share narrow ecological niches.  Hence conservation of such microhabitats becomes inevitable as far as these vulnerable habitats are concerned as they are prone to many human-induced threats along with biological invasions.  Natural calamities such as landslides and forest fires and anthropogenic activities including quarrying and urbanization reduce the natural vegetation of these unique habitats.  Hence, conservation strategies have to be formulated for the maintenance of floristic diversity in these unique ecosystems.

 

 

Table 1. Distribution of wet phase floristic elements in different microhabitats.

 

 

Botanical name

Family

Micro-habitats

1

Aeschynomene indica L.

Fabaceae

SEP, SFD

2

Alysicarpus bupleurifolius (L.) DC.

Fabaceae

SFD

3

Alysicarpus heterophyllus (Baker) Jafri & Ali

Fabaceae

SFD

4

Alysicarpus monilifer (L.) DC.

Fabaceae

SFD

5

Alysicarpus vaginalis (L.) DC.

Fabaceae

ERS, SFD

6

Bulbostylis barbata (Rottb.) C.B.Clarke

Cyperaceae

B, ERS, RCF

7

Bulbostylis puberula Kunth

Cyperaceae

SEP, RCF

8

Burmannia coelestis D.Don

Burmanniaceae

ERS, EFV

9

Centranthera indica (L.) Gamble

Orobanchaceae

ERS, SFD

10

Centranthera tranquebarica (Spreng.) Merr.

Orobanchaceae

SEP, SFD

11

Chamaecrista absus (L.) H.S.Irwin & Barneby

Fabaceae

SFD, SRA

12

Chamaecrista kleinii (Wight & Arn.) V.Singh

Fabaceae

SFD

13

Chamaecrista mimosoides (L.) Greene

Fabaceae

ERS, SFD

14

Chamaecrista nictitans subsp. patellaria (Collad.) H.S.Irwin & Barneby

Fabaceae

ERS, SFD

15

Cheilanthes opposita Kaulf.

Pteridaceae

B

16

Chrysopogon aciculatus (Retz.) Trin.

Poaceae

SRA

17

Commelina clavata C.B.Clarke

Commelinaceae

SFD, SRA

18

Commelina diffusa Burm.f.

Commelinaceae

SFD, SRA

19

Commelina wightii Raizada

Commelinaceae

ERS, SFD

20

Crotalaria linifolia L.f.

Fabaceae

SFD

21

Crotalaria nana Burm.f.

Fabaceae

SFD

22

Cyanotis arachnoidea C.B.Clarke

Commelinaceae

RCF

23

Cyanotis axillaris (L.) D.Don ex Sweet

Commelinaceae

ERS, SEP

24

Cyanotis burmanniana Wight

Commelinaceae

SFD

25

Cyanotis cristata (L.) D.Don

Commelinaceae

SRA

26

Cyanotis papilionacea (Burm.f.) Schult. & Schult.f.

Commelinaceae

EFV, ERS, RCF

27

Cyperus clarkei T.Cooke

Cyperaceae

SFD

28

Cyperus compressus L.

Cyperaceae

SFD

29

Cyperus cyperinus (Retz.) Suringar

Cyperaceae

SFD

30

Cyperus dubius Rottb.

Cyperaceae

SFD

31

Cyperus iria L.

Cyperaceae

SEP

32

Cyperus maderaspatanus Willd.

Cyperaceae

ERS, RCF

33

Cyperus rotundus L.

Cyperaceae

SFD

34

Desmodium triflorum (L.) DC.

Fabaceae

ERS, SFD

35

Dipcadi montanum (Dalzell) Baker

Asparagaceae

SFD

36

Dopatrium junceum (Roxb.) Buch.-Ham. ex Benth.

Plantaginaceae

SEP

37

Dopatrium nudicaule (Willd.) Benth.

Plantaginaceae

SEP

38

Drosera burmanni Vahl

Droseraceae

ERS, EFV

39

Drosera indica L.

Droseraceae

ERS, EFV

40

Eclipta prostrata (L.)L.

Asteraceae

SRA

41

Eragrostis unioloides (Retz.) Nees ex Steud.

Poaceae

ERS, SFD, SRA

42

Eriocaulon pectinatum Ruhland

Eriocaulaceae

EFV, ERS

43

Eriocaulon thwaitesii Körn.

Eriocaulaceae

EFV, ERS

44

Eriocaulon xeranthemum Mart.

Eriocaulaceae

EFV, ERS

45

Fimbristylis aestivalis Vahl

Cyperaceae

RCF, SFD

46

Fimbristylis argentea (Rottb.) Vahl

Cyperaceae

SFD

47

Fimbristylis falcata (Vahl) Kunth

Cyperaceae

SFD

48

Fimbristylis littoralis Gaudich.

Cyperaceae

SFD

49

Fimbristylis microcarya F.Muell.

Cyperaceae

SFD, SEP

50

Fimbristylis polytrichoides

 (Retz.) Vahl

Cyperaceae

RCF, SFD

51

Fimbristylis schoenoides (Retz.) Vahl 

Cyperaceae

SEP, SFD

52

Geissaspis cristata Wight & Arn.

Fabaceae

ERS, SFD

53

Geissaspis tenella Benth.

Fabaceae

ERS, SFD

54

Glinus oppositifolius (L.) Aug.DC.

Molluginaceae

SFD

55

Henckelia incana (Vahl) Spreng.

Gesneriaceae

RCF

56

Hoppea fastigiata (Griseb.) C.B.Clarke 

Gentianaceae

ERS, SFD

57

Hydrilla verticillata (L.f.) Royle 

Hydrocharitaceae

RP

58

Hygrophila ringens (L.) R.Br. ex Spreng.

Acanthaceae

SFD

59

Indigofera uniflora Roxb.

Fabaceae

ERS, SFD

60

Ipomoea aquatica Forssk.

Convolvulaceae

SEP, RP

61

Ipomoea marginata (Desr.) Verdc.

Convolvulaceae

SFD, SEP

62

Isoetes coromandeliana L.f.

Isoetaceae

SFD

63

Limnophila aromatica (Lam.) Merr.

Plantaginaceae

SEP, SFD

64

Limnophila heterophylla (Roxb.) Benth.

Plantaginaceae

SEP, SFD

65

Lindernia anagallis (Burm.f.) Pennell

Linderniaceae

SFD

66

Lindernia antipoda (L.) Alston

Linderniaceae

SFD

67

Lindernia caespitosa (Blume) Panigrahi

Linderniaceae

SFD

68

Lindernia ciliata (Colsm.) Pennell

Linderniaceae

EFV, ERS, SFD

69

Lindernia crustacea (L.) F.Muell.

Linderniaceae

SFD

70

Lindernia hyssopioides (L.) Haines

Linderniaceae

SFD

71

Lindernia nummulariifolia (D.Don) Wettst.

Linderniaceae

SFD, SEP

72

Lindernia rotundifolia (L.) Alston

Linderniaceae

SFD, SEP

73

Lobelia alsinoides Lam.

Campanulaceae

ERS, SFD

74

Ludwigia adscendens (L.) H.Hara

Onagraceae

RP

75

Ludwigia hyssopifolia (G.Don) Exell

Onagraceae

SFD

76

Marsilea quadrifolia L.

Marsileaceae

SEP, RP

77

Melochia corchorifolia L.

Malvaceae

SFD, SRA

78

Microcarpaea minima (K.D.Koenig ex Retz.) Merr.

Plantaginaceae

SFD

79

Mitrasacme indica Wight

Loganiacaeae

SFD

80

Mitrasacme pygmaea R.Br.

Loganiacaeae

SFD

81

Monochoria vaginalis (Burm.f.) C.Presl

Pontederiaceae

SEP

82

Murdannia semiteres (Dalzell) Santapau

Commelinaceae

EFV, ERS

83

Murdannia spirata (L.) G.Brückn.

Commelinaceae

SFD

84

Nymphaea nouchali Burm.f.

Nymphaeaceae

RP

85

Oldenlandia corymbosa L.

Rubiaceae

SFD, RCF

86

Oldenlandia diffusa (Willd.) Roxb.

Rubiaceae

SFD

87

Oldenlandia dineshii Sojan & Suresh

Rubiaceae

ERS, SFD

88

Ophioglossum nudicaule L.f.

Ophioglossaceae

SFD

89

Oryza rufipogon Griff.

Poaceae

SFD

90

Osbeckia muralis Naudin

Melastomataceae

B, ERS, RCF, SFD

91

Oxalis corniculata L.

Oxalidaceae

B, SFD

92

Pandanus canaranus Warb.

Pandanaceae

RP

93

Parahemionitis cordata (Hook. & Grev.) Fraser-Jenk.

Pteridaceae

B

94

Parasopubia delphiniifolia (L.) H.-P.Hofm. & Eb.Fisch.

Orobanchaceae

ERS, SFD

95

Polygala chinensis L.

Polygalaceae

SFD

96

Polygala persicariifolia DC.

Polygalaceae

ERS, RCF

97

Rhamphicarpa fistulosa (Hochst.) Benth.

Orobanchaceae

ERS, SFD

98

Rhynchosia rufescens (Willd.) DC.

Fabaceae

RCF, SFD

99

Rhynchosia suaveolens (L.f.) DC.

Fabaceae

RCF, SFD

100

Rotala indica (Willd.) Koehne

Lythraceae

SEP

101

Rotala malampuzhensis R.VNair

Lythraceae

SEP

102

Rotala mexicana Schltdl. & Cham.

Lythraceae

SEP, RP

103

Sesamum prostratum Retz.

Pedaliaceae

ERS, SFD

104

Setaria pumila (Poir.) Roem. & Schult.

Poaceae

SFD, SRA

105

Sida acuta Burm.f.

Malvaceae

SFD, SRA

106

Smithia blanda Wall.

Fabaceae

SFD

107

Smithia conferta Sm.

Fabaceae

SFD

108

Spermacoce alata Aubl.

Rubiaceae

SRA

109

Spermacoce articularis L.f.

Rubiaceae

SRA

110

Spermacoce hispida L.

Rubiaceae

SRA

111

Spermacoce ocymoides Burm.f.

Rubiaceae

SFD, SRA

112

Spermacoce pusilla Wall.

Rubiaceae

RCF, SFD

113

Striga angustifolia (D.Don) C.J. Saldanha

Orobanchaceae

ERS, SFD

114

Striga asiatica (L.) Kuntze

Orobanchaceae

ERS, SFD

115

Tephrosia maxima (L.) Pers.

Fabaceae

SFD, SRA

116

Tephrosia purpurea (L.) Pers.

Fabaceae

ERS, SFD, SRA

117

Utricularia aurea Lour.

Lentibulariaceae

RP

118

Utricularia lazulina P.Taylor

Lentibulariaceae

EFV

119

Utricularia graminifolia Vahl 

Lentibulariaceae

EFV

120

Xyris pauciflora Willd.

Xyridaceae

ERS

121

Zornia gibbosa Span.

Fabaceae

ERS, SFD

 

EFV—Ephemeral flush vegetation | SEP—Small ephemeral pool | RP—Rock pool | ERS—Exposed rock surface | RCF—Rocky crevice and fissure | SFD—Soil-filled depression | SRA—Soil rich area | B—Boulder.

 

 

For images – click here

 

References

 

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Cruz, E.D., P.K.R. Nair & V. Prasannakumar (2000). Palghat Gap-A dextral shear zone from the south Indian granulite terrain. Gondwana Research 3(1): 21–31. https://doi.org/10.1016/S1342-937X(05)70054-X

Fitzsimons, J.A. & D.R. Michael (2017). Rocky outcrops: A hard road in the conservation of critical habitats. Biological Conservation 211: 36–44. https://doi.org/10.1016/j.biocon.2016.11.019

Hopper, S.D. & P.C. Withers (1997). Granite outcrops symposium proceedings, September 14–15, 1996. Journal of the Royal Society of Western Australia 80: 87–237.

IUCN (2019). The IUCN Red List of Threatened Species. Version 2019-2. http://www.iucnredlist.org. Downloaded on 01 September 2019.

Jose, S., V. Suresh, R. Prakashkumar & P.V. Madhusoodanan (2013). Dipcadi montanum (Dalzell) Baker - An addition to the flora of Kerala, India. Journal of Bombay Natural History Society 110(3): 237.

Jose, S., M.C. Nair, K.M. Prabhukumar, V.V. Asha, R.P. Kumar, P.V. Madhusoodanan & V. Suresh (2015). Oldenlandia dineshii (Rubiaceae: Spermacoceae), a new species from the Palakkad Gap region of Western Ghats, India. Kew Bulletin 70(13): 1–5. https://doi.org/10.1007/s12225-015-9564-y

Pramod, C., A.K. Pradeep & C.C. Harilal (2014). Seasonal pools on lateritic plateaus: Unique habitats of great diversity - a case study from northern Kerala. Journal of Aquatic Biology and Fisheries 2: 458–466.

Sasidharan, N. (2014). Flowering plants of Kerala, Version 2.0. CD Rom. KFRI, Peechi. Accessed on 01 September 2019.

Sreejith, K.A., P. Prashob, V.B. Sreekumar, H.P. Manjunatha & M.P. Prejith (2016). Microhabitat diversity in a lateritic hillock of northern Kerala, India. Vegetos 29(3): 1–11.