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6.1 General Discussion:
The present work is the outcome of
2012. The study was aimed to serve the purpose of an inventory of the monocot flora of
erstwhile Kamrup District, with
The study was based on extensive field and herbarium works
contribution of ‘Monocot flora’
investigator along with critical examination of
deposited in Kanjilal Herbarium, Shillong.
The study recorded 193 genera
The details of habit and habitat
is given below (Fig. 1 and Fig. 2)
family Poaceae is followed by Cyperaceae, then by Araceae.
dominant families of the study area.
319
Chapter 6: DISCUSSION
The present work is the outcome of a comprehensive study made during the period 2007
aimed to serve the purpose of an inventory of the monocot flora of
ct, with special reference to grasses and sedges of Assam.
extensive field and herbarium works. The thesis is an original
‘Monocot flora’ based on extensive collection of plant materials by the
investigator along with critical examination of large number of herbarium materials
deposited in Kanjilal Herbarium, Shillong.
and 371 species belonging to 31 families (Table 6).
s of habit and habitat analysis of the monocot flora of erstwhile Kamrup district
(Fig. 1 and Fig. 2). Out of the 31 families present in the District, the largest
family Poaceae is followed by Cyperaceae, then by Araceae. Fig. 3 provides
dominant families of the study area.
Fig.1: Habit analysis
Herbs
Shrubs
Trees
Undershrub
made during the period 2007-
aimed to serve the purpose of an inventory of the monocot flora of
Assam.
is an original
based on extensive collection of plant materials by the
of herbarium materials
Table 6).
Kamrup district
. Out of the 31 families present in the District, the largest
provides the ten
Herbs
Shrubs
Trees
Undershrub
320
Fig. 2: Habitat analysis
Fig. 3: Dominant monocot families of the study area according to their strength in the no.
of species.
Aquatic
Terrestrial
Epiphytic
Climbers
Creepers
Marshy Areas
0
20
40
60
80
100
120
No
. o
f sp
eci
es
321
Table 1 and 2 provides a comparative study of 6 leading monocot families of the study
area with Assam and India and with two neighbouring districts - Kokrajhar and
Bongaingaon.
In the order of dominance at the generic level, Cyperus is the largest genera with 22
species, followed by Bambusa with 10 species and then by Fimbristylis with 9 species
Table 3 provides seven dominant genera of the study area.
Table 1: Comparative study of six dominant monocot families of the study area with
Assam and India
Families
Study area
Genera/Species
Assam (Baishya, 1999)
Genera/Species
India (Karthikeyan,
2000)
Poaceae 54/100 83/212 263 /1291
Cyperaceae 14/57 15/81 38 /545
Araceae 20/34 18/47 28/167
Zingiberaceae 10/27 13/ 36 22 /178
Orchidaceae 17/22 81/191 184/1229
Arecaceae 15/21 16/37 24/102
Table 2: A comparitive study of six dominant monocot families of the study area with
Kokrajhar and Bongaigaon districts of Assam
Families
Study Area
Genus/Species
Kokrajhar Dist.
Genus/Species
(Daimary, 2011)
Bongaigaon Dist.
Genus/Species
(Borah, 2008)
Poaceae 54/100 33/46 38/56
322
Cyperaceae 14/57 6/25 6/10
Araceae 20/34 12/16 13/19
Zingiberaceae 10/27 5/11 7/13
Orchidaceae 17/22 17/21 12/18
Arecaceae 15/21 4/5 10/13
Table 3: Numerical representation of 7 dominant genera of monocots of the study area
Name of Genera Family No. of Species
Cyperus Cyperaceae 22
Bambusa Poaceae 10
Fimbristylis Cyperaceae 09
Commelina Commelinaceae 07
Panicum Poaceae 06
Musa Musaceae 06
Zingiber Zingiberaceae 06
The diversity in the flora of the study area is very high. An analysis of generic diversity
under family, species diversity under family and species diversity under genera are
provided in Tables 3, 4 and 5.
Table 3: Generic diversity under family
families with 01 genus……….12
families with 02 genera……….04
323
families with 03 genera……….03
families with 04 genera……….02
families with 05 genera……….02
families with 08 genera……….02
families with 10 genera……….01
families with 14 genera……….01
families with more than 15 genera……….04
Table 4: Species diversity under family
families with 01 species……….06
families with 02 species……….06
families with 03 species……….05
families with 04 species……….01
families with 05 species……….01
families with 06 species……….01
families with 11 species……….01
families with 12 species……….01
families with 16 or more species……….08
Table 5: Species diversity under genera
genera with 01 species……….121
genera with 02 species……….34
genera with 03 species……….15
genera with 04 species……….09
genera with 05 species……….06
324
genera with 06 species……….03
genera with 07 or more species……….04
Table 6: Conspectus of families showing number of genera and species
Sl. No. Family Genera Species
01 Agavaceae 08 16
02 Amaryllidaceae 08 12
03 Araceae 20 34
04 Arecaceae 15 21
05 Alliaceae 01 02
06 Alismataceae 02 02
07 Bromeliaceae 04 05
08 Cannaceae 01 01
09 Commelinaceae 05 16
10 Costaceae 01 01
11 Cyperaceae 14 57
12 Dioscoreaceae 01 04
13 Eriocaulaceae 01 04
14 Haemodoraceae 01 01
15 Heliconiaceae 01 03
16 Hydrocharitaceae 03 03
17 Hypoxidaceae 02 02
18 Iridaceae 03 03
19 Juncaceae 01 01
325
20 Lemnaceae 03 03
21 Liliaceae 05 06
22 Marantaceae 04 11
23 Musaceae 01 06
24 Orchidaceae 17 22
25 Pandanaceae 01 02
26 Poaceae 54 100
27 Pontederiaceae 02 02
28 Smilacaceae 01 01
29 Strelitziaceae 02 02
30 Taccaceae 01 01
31 Zingiberaceae 10 27
6.2 Significant findings:
Endemic taxa recorded in the present study:
As many as 102 endemic species belonging to 75 genera have been recorded for Assam
(Nayar, 1980). The present study recorded 16 monocot species endemic to Assam, N. E.
India and India (Table 8).
Table 8: Endemic taxa recorded during the present study
Sl. No. Name of the taxa Region Reference
1. Arundinella decempedalis N. E. India, Sikkim and
West Bengal
Nair and Thomas,
2001
2. Bambusa arudinacea India Ahmedullah and
Nayar, 1987
326
3. Bambusa balcooa Assam and West Bengal Nair and Thomas,
2001
4. Bambusa pallida N. E. and Sikkim Nair and Thomas,
2001
5. Cymbopogon martinii India Ahmedullah and
Nayar, 1987
6. Dioscorea pentaphylla Assam Baishya, 1999
7. Dendrobium densiflorum N. E. India Kataki et al., 1984
8. Dendrobium nobile N. E. India Kataki et al., 1984
9. Homalomena aromatica N. E. India Choudhury and
Murti, 2000
10. Hymenachne assamica N. E. India Choudhury and
Murti, 2000
11. Livistona jenkinsiana N. E. India Choudhury and
Murti, 2000; Nayar,
1996
12. Musa velutina N. E. India and Sikkim Choudhury and
Murti, 2000; Nayar,
1996
13. Pinanga gracilis N. E. India and Sikkim Nayar, 1996
14 Parakaempferia synantha Assam Baishya, 1999
15. Schizostachyum pergracile Assam Baishya, 1999
16. Schizostachyum
polymorphum
N. E. India Nair and Thomas,
2001
327
RET plants recorded during the present study:
Baishya (1999) provided a list of 60 rare, endangered and threatened species from Assam.
The present study recorded a total of 26 RET taxa (Table 9).
Table 9: RET monocot plants recorded in the study area
Sl. No. Botanical name Status Reference
1. Acampe papillosa E Choudhury and Murti, 2000 (CITES)
2. Acorus calamus C Choudhury and Murti, 2000 (CITES)
3. Aerides multiflora E Choudhury and Murti, 2000 (CITES)
4. Aerides odorata E Choudhury and Murti, 2000 (CITES)
5. Arundina graminifolia E Choudhury and Murti, 2000 (CITES)
6. Asparagus racemosus V Choudhury et al., 2002
7. Costus speciosus E Choudhury et al., 2002
8. Cyperus platystylis E Chowdhury, 2005
9. Cyperus difformis E Chowdhury, 2005
10. Cymbidium aloifolium E Choudhury and Murti, 2000 (CITES)
11. Dendrobium aphyllum E Choudhury and Murti, 2000 (CITES)
12. Dioscorea alata E Choudhury et al., 2002
13. Dioscorea bulbifera E Choudhury et al., 2002
14. Globba clarkei E Nayar and Sastry, 2000
15. Hedychium coronarium E Chowdhury, 2005
16. Hyophorbe
lagenicaulis
C Choudhury and Murti, 2000 (CITES)
17. Kaempferia galanga E Chowdhury, 2005
18. Musa ornata E Chowdhury, 2005
328
19. Papilionanthe teres E Choudhury and Murti, 2000 (CITES)
20. Pholidota articulata E Choudhury and Murti, 2000 (CITES)
21. Rhyncostylis retusa E Choudhury and Murti, 2000 (CITES)
22. Tacca integrifolia E Baishya, 1999
23. Vanda coerulea R Kameswara Rao et al., 2003
24. Vanilla pilifera R Baishya, 1999
25. Zeuxine longilabris E Chowdhury, 2005
26. Zeuxine goodyeroides E Chowdhury, 2005
R- Rare; E- Endangered; T- Threatened; C- Critically endangered
Grasses not recorded by Bor (1940):
The grass species which were not recorded by Bor (1940) but are recorded during the
present study are Alopecurus aequalis Sobol, Bambusa assamica Baruah et Borthakur,
Bambusa garuchokua Baruah et Borthakur, Bambusa rangaensis Baruah et Borthakur,
Isachne globosa (Thunb) O. Ktze. and Sorgham caudatum (L.) Moench.
Sedges not recorded by Rao and Verma (1982):
The sedges not recorded by Rao and Verma (1982) in their work on cyperaceae of North-
East India but recorded during the present study includes Cyperus alopecuroides Rottb., C.
fuscus L., C. imbricatus Retz., C. involucratus Rottb. and C. michelianus subsp. pygmaeus
(Rottb.) Asch. and Graebn.
New addition to the monocot flora of Assam:
The present study recorded two monocot species viz., Caldesia parnassifolia (Bassi ex L.)
Parl. and Commelina communis L., which were not recorded by earlier workers.
329
6.3 Seasonal Variation:
Climate change is a natural phenomenon that has occurred throughout the history of the
earth and it has important implications for nearly every aspect of life on earth.
The study area, erstwhile Kamrup District of Assam, is situated in humid sub-tropical
region. The district experiences a hot summer followed by monsoon season of heavy
rainfall and a relatively cool winter with scanty rainfall. As such, a seasonal variation of
monocot flora was observed and recorded (Table 10). From the study it is observed that
the monocot flora flourishes mostly in the monsoon season.
Depending on the climatic condition, variations seen is grouped into four distinct
categories as given below:
Winter -November to February
Pre-monsoon - March-May
Monsoon - June-September
Post-monsoon - October-November
Table 10: List of monocot plant species showing seasonal variation
Name of the family and Plant species Winter Pre-
Monsoon
Monsoon Post-
Monsoon
Hydrocharitaceae
Hydrilla verticillata + + + +
Ottelia alismoides + - - +
Vallisneria spiralis - - + +
Orchidaceae
330
Acampe papillosa - + - -
Aerides multiflora - + + -
Aerides odorata - + + -
Arundina graminifolia - + - -
Cymbidium aloifolium - + + -
Dendrobium aphyllum - + - -
Dendrobium densiflorum - + - -
Dendrobium fimbriatum - + - -
Dendrobium lindleyi - + - -
Eria alba - + + -
Goodyera procera + + - -
Otoglossum globuliferum - + + +
Papilionanthe teres - + + -
Phaius tancarvilleae - + + -
Pholidota articulata - + - -
Rhyncostylis retusa - + - -
Spathoglottis plicata - + + -
Stichorkis viridiflora - + - -
Vanda coerulea - + - -
Vanilla pilifera - + - -
Zeuxine longilabris - + + -
Zeuxine goodyeroides - + + -
Iridaceae
Belamcanda chinensis - + + -
331
Gladiolus sp. + + + +
Neomarica gracilis + + - -
Musaceae
Musa assamica + + + +
Musa balbisiana + + + +
Musa ornata + + + +
Musa paradisiaca + + + +
Musa sanguinea + + + +
Musa velutina + + + -
Heliconiaceae
Heliconia rostrata + + + +
Heliconia psittacorum - + + -
Heliconia orthotricha - + + -
Strelitziaceae
Ravenala madagascariensis - - + -
Strelitzia reginae - + + -
Costaceae
Costus speciosus + + + -
Zingiberaceae
Alpinia galanga - + + +
Alpinia nigra - + + +
Alpinia calcarata - + + +
Amomum aromaticum + + + +
Amomum dealbatum - + + -
332
Amomum subulatum - + + +
Curcuma angustifolia - - + -
Curcuma amada - - + -
Curcuma longa + - - +
Curcuma aromatica - + +
Curcuma caesia - - -
Etlingera linguiformis - - + +
Globba clarkei - - + +
Globba multiflora - - + +
Hedychium coccineum - - + +
Hedychium coronarium + - + +
Hedychium spicatum - - - +
Kaempferia galanga - - + -
Kaempferia rotunda - + - -
Parakaempferia synantha - - - +
Zingiber montanum - - + -
Zingiber officinale - - - +
Zingiber rubens - - + -
Zingiber zerumbet - - + +
Zingiber capitatum - - + +
Zingiber chrysanthum - - + +
Cannaceae
Canna indica + + + +
Marantaceae
333
Calathea bella - - + -
Calathea lancifolia - - + -
Calathea majestica - - + -
Calathea rufibarba - - + -
Ctenanthe burle-marxii + + + +
Maranta leuconeura var. kerchoveana - + + -
Maranta leuconeura var. erythroneura - + + -
Maranta arundinacea + + + -
Maranta cristata - + - -
Maranta lietzei - + + -
Schumannianthus dichotomus - + + -
Bromeliaceae
Ananas comosus + - - -
Billbergia amoena - - + -
Billbergia brasiliensis + + + +
Neoregelia spectabilis - + + -
Tillandsia cyanea - + + -
Taccaceae
Tacca integrifolia - + + -
Haemodoraceae
Ophiopogon intermedius - + + +
Hypoxidaceae
Curculigo orchioides - - + -
Molineria capitulata - - + -
334
Amaryllidaceae
Amaryllis belladonna + + - -
Crinum amoenum - + + -
Crinum asiaticum - - + +
Crinum latifolium - - + -
Eucharis amazonica - - + +
Hippeastrum puniceum - - + -
Hymenocallis littoralis - - + -
Proiphys amboinensis - + + -
Scadoxus multiflorus - + - -
Zephyranthes candida - - + +
Zephyranthes citrina - - + +
Zephyranthes rosea - - + +
Dioscoreaceae
Dioscorea alata - - - +
Dioscorea bulbifera - - + +
Dioscorea hispida - + + -
Dioscorea pentaphylla + - + +
Agavaceae
Agave americana - + + +
Agave vivipara - + + +
Beaucarnea recurvata - - + +
Cordyline fruticosa + + + +
Dracaena angustifolia - + + -
335
Dracaena fragans + + + +
Dracaena marginata + + + +
Dracaena terniflora - - + -
Dracaena reflexa + + + +
Furcraea foetida + + + +
Polianthes tuberosa - - + -
Sansevieria cylindrica + + + +
Sansevieria kirkii - + - -
Sansevieria roxburghiana + + + -
Sansevieria trifasciata + + + +
Yucca gloriosa - - + -
Liliaceae
Aloe vera + + - -
Asparagus racemosus - - + -
Asparagus filicinus - + + -
Chlorophytum comosum - - + -
Gloriosa superba - - + +
Peliosanthes teta + + - -
Alliaceae
Allium cepa + + - -
Allium sativum + + - -
Commelinaceae
Commelina benghalensis - - + +
Commelina carolina - - + +
336
Commelina communis - - + +
Commelina diffusa - + + +
Commelina longifolia - - + +
Commelina paludosa - - + +
Commelina suffruticosa - - + +
Cyanotis cristata - - + -
Floscopa scandens - - + +
Murdannia japonica - + + -
Murdannia nudiflora - - + +
Murdannia spirata + - + +
Tradescantia pallida - + + -
Tradescantia sillamontana - + + +
Tradescantia spathacea + + + +
Tradescantia zebrina + + + +
Smilacaceae
Smilax zeylanica + - + +
Pontederiaceae
Eichhornia crassipes + - + +
Monochoria hastata - - - +
Alismataceae
Caldesia parnassifolia - + + +
Sagittaria sagittifolia - - + -
Arecaceae
Areca catechu + - - +
337
Areca triandra + + + +
Bismarckia nobilis - + + -
Borassus flabellifer + + - -
Calamus tenuis + - + +
Caryota mitis + + + +
Caryota urens - + - -
Chamaedorea metallica + + + +
Chamaedorea seifrizii + + + +
Cocos nucifera + + + +
Dypsis lutescens - - + -
Hyophorbe lagenicaulis + + + +
Licuala grandis - - + -
Licuala peltata + + - +
Livistona chinensis - - + -
Livistona jenkinsiana - - + -
Phoenix dactylifera - + + -
Phoenix sylvestris + + + +
Pinanga gracilis + + + +
Rhapis excelsa - - + -
Roystonea regia + + + -
Araceae
Acorus calamus - + + -
Anthurium andreanum + + + +
Anthurium clarinervium + + + +
338
Anthurium crystallinum + + + +
Anthurium panduriforme + + + +
Aglaonema commutatum + + + +
Alocasia cucullata - + + -
Alocasia clypeolata + + + +
Alocasia longiloba - - + +
Alocasia indica - - + +
Alocasia odora + - + +
Amorphophallus bulbifer - + + +
Caladium bicolor - - + +
Caladium lindenii + + + +
Cercestis mirabilis + + + +
Colocasia esculenta - - + +
Colocasia fallax - + + +
Dieffenbachia seguine + + + +
Homalomena aromatica - + + +
Lasia spinosa - - + +
Monstera deliciosa - - + +
Philodendron bipinnatifidum - + + +
Philodendron erubescens - + + +
Philodendron gloriosum - + + +
Philodendron pedatum - + + +
Philodendron pinnatilobum - + + +
Pistia stratiotes - - + +
339
Pothos scandens - + + -
Scindapsus pictus - + + +
Spathiphyllum commutatum - + + -
Spathiphyllum wallisii - + + -
Syngonium podophyllum - + + -
Typhonium trilobatum - + + -
Xanthosoma sagittifolium - - + +
Pandanaceae
Pandanus odorifer + + + +
Pandanus tectorius + + + +
Cyperaceae
Actinoscirpus grossus - - + +
Carex cruciata - + + -
Carex finitima - - + -
Courtoisina cyperoides - - + -
Cyperus alopecuroides. - + + -
Cyperus cephalotes + + - +
Cyperus cyperoides subsp. cyperoides - - + +
Cyperus compressus - + + +
Cyperus compactus + - + +
Cyperus cuspidatus - - + +
Cyperus cyperinus - + + -
Cyperus diffusus + + + +
Cyperus difformis - - + +
340
Cyperus digitatus + - + +
Cyperus distans + - + +
Cyperus fuscus - - + -
Cyperus halpan - - + +
Cyperus imbricatus - - + +
Cyperus involucratus - - + +
Cyperus iria + + + +
Cyperus michelianus subsp. pygmaeus + + - -
Cyperus niveus - + + +
Cyperus pilosus - + + +
Cyperus platystylis - - + +
Cyperus rotundus - + + +
Cyperus tenuispica - - + +
Eleocharis acutangula - - + +
Eleocharis congesta + + + +
Eleocharis geniculata + - + +
Eleocharis pellucida - + + +
Fimbristylis aestivalis + + - +
Fimbristylis acicularis + - + +
Fimbristylis bisumbellata + + - -
Fimbristylis complanata - - + -
Fimbristylis dichotoma - + + +
Fimbristylis littoralis - - + -
Fimbristylis schoenoides - - + +
341
Fimbristylis squarrosa - - + +
Fimbristylis umbellaris - - + -
Fuirena umbellata + - + +
Kyllinga brevifolia - + + +
Kyllinga odorata - - + -
Lipocarpha chinensis - + + +
Lipocarpha gracilis - - + +
Lipocarpha squarrosa - - + -
Pycreus flavidus - - + +
Pycreus polystachyos - - + +
Pycreus pumilus - - + +
Pycreus sanguinolentus + - + +
Pycreus stramineus - - + +
Rhynchospora rubra - + + -
Schoenoplectiella articulata - + + +
Schoenoplectiella juncoides - - + +
Schoenoplectiella supina - - + +
Scirpus cyperinus - - + -
Scleria parvula - - + -
Scleria terrestris - + + +
Juncaceae
Juncus prismatocarpus - + + +
Eriocaulaceae
Eriocaulon achiton - - + +
342
Eriocaulon brownianum + + + +
Eriocaulon cristatum + - - +
Eriocaulon truncatum + + + +
Poaceae
Acroceras munroanum - + - -
Alloteropsis semialata + + + +
Alopecurus aequalis - + - -
Apluda mutica + + + +
Arundinella bengalensis + + + +
Arundinella decempedalis + + + +
Arundinella pumila - - + +
Arundo donax + + + +
Axonopus compressus + + + +
Bambusa arundinaceae - + + +
Bambusa assamica + + + +
Bambusa balcooa - + + +
Bambusa garuchokua + + + +
Bambusa multiplex + + + +
Bambusa pallida - + + +
Bambusa polymorpha + + + +
Bambusa rangaensis + + + +
Bambusa tulda - + + +
Bambusa vulgaris var. vittata + + + +
Bambusa vulgaris f. waminii + + + +
343
Brachiaria distachya + - + +
Brachiaria mutica + - + +
Brachiaria ramosa + - + +
Chrysopogon aciculatus - + + +
Coix lacryma-jobi - + + +
Cymbopogon citratus - - + +
Cymbopogon martini - - + -
Cymbopogon nardus - - + +
Cynodon dactylon + + + +
Cyrtococcum accrescens + + + +
Dactyloctenium aegyptium - - + +
Dendrocalamus giganteus + + + +
Dendrocalamus hamiltonii + + + +
Dicanthium assimile + - + +
Digitaria compacta + - + +
Digitaria longiflora - + + -
Digitaria stricta - - + -
Echinochloa colonum + - + +
Echinochloa crus-galli - - + +
Echinochloa crus-pavonis - + + -
Echinochloa stagnina - - + -
Eleusine indica + + + +
Eragrostis gangetica - + - +
Eragrostis nigra + + + +
344
Eragrostis tenella - - + +
Eragrostis unioloides + + + +
Eragrostis zeylanica - + + -
Erianthus longisetosus + - - -
Eulalia trispicata + - + +
Hackelochloa granularis - - + +
Hemarthria compressa - - + -
Hemarthria protensa - + + -
Heteropogon contortus - - + -
Hymenachne assamica - - - +
Isachne globosa + + + +
Imperata cylindrica + + - -
Leersia hexandra + + + +
Leptochloa chinensis - - + -
Melocanna baccifera + + + +
Oplismenus burmannii + + + +
Oplismenus compositus + + + +
Oryza meyeriana - - + -
Oryza sativa - + + +
Panicum auritum + + + +
Panicum brevifolium - + + +
Panicum maximum + + - -
Panicum humile - + + +
Panicum montanum - - + +
345
Panicum paludosum - - + +
Paspaladium flavidium + + + +
Paspaladium punctatum - - + +
Paspalum conjugatum + - + +
Paspalum scrobiculatum + + + +
Phyllostachys edulis - + + +
Pogonotherum crinitum - + + -
Pogonotherum paniceum + + - +
Polytoca digitata + - + +
Polytoca wallichiana - + + +
Pennisetum americanum + - + +
Pennisetum purpureum + - - -
Phragmites karka + - + +
Rottboellia cochinchinensis + + + +
Schizostachyum pergracile - + + +
Schizostachyum polymorphum + + + +
Saccharum arundinaceum + + + +
Saccharum officinarum + - - -
Saccharum procerum + + - -
Saccharum rufipilum + - - +
Saccharum spontaneum L. + - - -
Secale cereale - + + +
Setaria palmifolia + + + +
Setaria pumila + + + +
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Setaria viridis - + + +
Sorghum caudatum - - - +
Sorghum nitidum + - + +
Sporobolus diander - - + +
Sporobolus fertilis - - + +
Themeda villosa + + + +
Thysanolaena maxima + + + +
Triticum aestivum - - + -
Vetiveria zizanioides + - + +
Zea mays - - + -
Lemnaceae
Lemna perpusilla - + + +
Spirodela polyrrhiza - + + +
Wolffia arrhiza - + + +
6.4 Phytogeography:
Phytogeography is the branch of biogeography that is concerned with the geographic
distribution of plant species and their influence on the earth’s surface. It is also concerned
with all the aspects of the plant distribution in present and past (Good, 1974). The
phytogegraphical studies of an area is important as well as necessary to find out the origin
and affinities of flora. Alexander von Humboldt (1769-1859) is considered as the “father
of phytogeography”. On the basis of climatic and geographical conditions, the earth is
generally divided into broad vegetational belts, accordingly our country is under tropical
zone. India is recognized as one of the 12 megadiversity hotspots of the world in terms of
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floristic composition. Legris and Meher-Homji (1963) recognised twenty five floristic
elements in the vegetation of India. N. P. Balakrishnan (1996) divided India into 11
phytogeographical regions viz., North-West Himalayas, Indo-Gangetic Plains, Eastern
Himalayas (Arunachal Pradesh and Sikkim), Assam (North-Eastern India), Central India,
Arid Zone, North Western Ghats and North West Coast, Southern Western Ghats,
Southern West Coast and Lakshadweep, Deccan, Eastern Ghats and Coromandel coast and
Andaman and Nicobar islands.
North-East India denotes the transition zone between the Indian Indo-Malayan and Indo-
Chinese biogeographic region and meeting point of Eastern Himalaya and Peninsular
India. Assam, a part of Eastern Himalaya has been recognized as distinct
phytogeographical area (Chatterjee, 1940; Clarke, 1898; Hooker, 1906; Sahni, 1981)
Generally, flora of Assam has Indo-Malayan affinity. The flora of Assam has affinity with
that of Western Ghats too (Arora, 1964). 35% of the floristic elements of the study area
has affinity to Indo-Malayan region, 14.9%, 14.3% and 12.5% has affinity to Pantropical,
Paleotropical and Neotropical region respectively. 6.4% of the elements are native and
1.3% are cosmopolitan.
The distribution of the reported monocot plant elements from the present study area are
discussed below:
1. Indian elements:
These are the indigenous plant species of India and the representative species of the study
area include Acorus calamus, Bambusa arundinacea, Bambusa pallida, Bambusa balcooa,
Calamus tenuis, Dendrobium lindleyi, Dendrobium aphyllum, Echinochloa crus-galli,
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Eriocaulon achiton, Fimbristylis umbellaris, Paspalum scrobiculatum, Schoenoplectiella
juncoides, Pinanga gracilis, Curcuma longa, Curcuma amada, Curcuma aromatica, etc.
2. Cosmopolitan elements:
These species are found throughout the whole world and the representative species are
Cynodon dactylon, Cyperus rotundus, Vallisneria spiralis, Pycreus polystachyos, Wolffia
arrhiza, etc.
3. Indo-Malayan elements:
These originated from Indo-Malayan region and the representative species are Apluda
mutica, Arundo donax, A. multiflora, Arundina graminifolia, Alocasia odora, Asparagus
filicinus, Bambusa tulda, Bambusa polymerpha, Costus speciosus, Cyanotis cristata,
Cyperus iria, Commelina benghalensis, Dendrobium densiflorum, D. fimbriatum,
Dactyloctenium aegypticum, Dendrocalamus hamiltonii, Fimbristylis bisumbellata,
Goodyera procera, Isachne globosa, Livistona chinensis, Oryza sativa, Ophiopogon
intermedius, Panicum humile, Pogonotherum crinitum, Vetiveria zizanioides, etc.
4. Paleotropical elements:
These species originated from Africa, Asia and America and the representative species are
Alloteropsis semialata, Asparagus racemosus, Caldesia parnassifolia, Cyperus
compressus, Eragrostis tenella, Eragrostis gangetica, Gloriosa superba, Hackelochloa
granularis, Hemarthria compressa, Imperata cylindrica, Panicum paludosum, Panicum
brevifolium, Rottboellia cochinchinensis, Setaria palmifolia, Scleria parvula, etc.
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5. Neotropical elements:
These species originated from America, Mexico, Carribean, South America and West
Indies and the representative species are Anthurium clarinervium, Agave vivipara, Agave
americana, Beaucarnea recurvata, Cyperus diffuses, C. halpan, C. difformis, Canna
indica, Eichhornia crassipes, Eucharis amazonica, Furcraea foetida, Heliconia rostrata,
Hymenocallis littoralis, Kyllinga brevifolia, Leersia hexandra, Polianthes tuberosa, etc.
6. Pantropical elements:
These species originated from Old World ie. Africa and Asia and the representative
species are Alopecurus aequalis, Billbergia amoena, Cyperus distans, Calathea lancifolia,
Cercestis mirabilis, Cyperus distans, Eleusine indica, Fuirena umbellata, Neoregelia
spectabilis, Oplismenus compositus, Oplismenus burmanni, Otoglossum globuliferum,
Philodendron pinnatilobum, Sporobolus fertilis, Tacca integrifolia, etc.
Fig. 4: Phytogeography of the monocot elements of the study area.
05
10152025303540
Flo
rist
ic e
lem
en
ts (
%)
Percentage of elements
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6.5 Utilitarian aspects of the flora:
The results include valuable information about traditional utilization of the wild plants and
of the introduced plants in our day to day life. Proper exploitation of these plants may lead
to forest-based cottage industries. A few important ones are listed below:
Ornamental plants recorded in the present study:
The present study revealed the existence of numerous monocot ornamental plants. They
are: Aglaonema commutatum, Aerides multiflora, Agave americana, Agave vivipara,
Alocasia clypeolata, Alocasia longiloba, Amaryllis belladonna, Anthurium andreanum,
Anthurium clarinervium, Anthurium crystallinum, Anthurium panduriforme, Areca
triandra, Asparagas racemosus, Asparagas filicinus, Bambusa vulgaris var. vitttata,
Bambusa vulgaris f. waminii, Beaucarnea recurvata, Billbergia amoena, Billbergia
brasiliensis, Belamcanda chinensis, Bismarkia nobilis, Caladium lindenii, Caladium
bicolor, Calathea bella, Calathea lancifolia, Calathea majestica, Calathea rufibarba,
Canna indica, Caryota mitis, Caryota urens, Cercestis mirabilis, Chlorophytum comosum,
Chamaedorea seifrizii, Colocasia fallax, Cordyline fruticosa, Crinum amoenum, Crinum
asiaticum, Crinum latifolium, Ctenanthe burle-marxii, Curculigo orchioides, Cyperus
involucratus, Dieffenbachia sanguine, Dendrobium densiflorum, Dendrobium lindleyi,
Dracaena angustifolia, Dracaena braunii, Dracaena fragans, Dracaena marginata,
Dracaena terniflora, Dracaena reflexa, Dypsis lutescens, Eucharis amazonica, Eria alba,
Furcraea foetida, Gladiolus sp., Hedychium coccineum, Hedychium spicatum, Heliconia
rostrata, Heliconia psittacorum, Heliconia orthotricha, Hippeastrum puniceum,
Hymenocallis littoralis, Hyophorbe lagenicaulis, Licuala grandis, Livistona jenkinsiana,
Livistona chinensis, Maranta leuconeura var. kerchoveana, Maranta leuconeura var.
erythroneura, Maranta arundinacea, Maranta cristata, Molineria capitulata, Monstera
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deliciosa, Musa ornata, Neoregelia spectabilis, Neomarica gracilis, Ophiopogon
intermedius, Otoglossum globuliferum, Pandanus odorifer, Philodendron bipinnatifidum,
Philodendron erubescens, Philodendron gloriosum, Philodendron pedatum, Philodendron
pinnatilobum, Pholidota articulata, Polianthes tuberosa, Proiphys amboinensis, Ravenala
madagascariensis, Rhapis excelsa, Rhyncostylis retusa, Roystonea regia, Sansevieria
cylindrica, Sansevieria kirkii, Sansevieria roxburghiana, Sansevieria trifasciata, Scadoxus
multiflorus, Scindapsus pictus, Spathiphyllum wallisii, Spathiphyllum commutatum,
Spathoglottis plicata, Syngonium podophyllum, Strelitzia reginae, Tillandsia cyanea,
Tradescantia pallida, Tradescantia sillamontana, Tradescantia spathacea, Tradescantia
zebrina, Yucca gloriosa, Zephyranthes candida, Zephyranthes citrina and Zephyranthes
rosea.
Medicinal Plants recorded in the present study:
It is estimated that about 3000 species of Indian flowering plants are of potential medicinal
value, of which 1300 species are extensively used in different systems of medicine such as
Ayurveda, Siddha, Unani and Allopathy (Sharma et al., 2001).The North-East India is a
store-house of numerous life-saving drug plants (Rao and Jamir, 1982). The medicinally
important monocot plants recorded in the present study area are Acorus calamus, Aerides
odorata, Allium cepa, Allium sativum, Aloe vera, Alocasia indica, Alpinia galanga,
Alpinia nigra, Amaryllis belladonna, Amorphophallus bulbifera, Amoemum aromaticum,
Ananas comosus, Asparagus racemosus, Areca catechu, Borassus flabellifer, Canna
indica, Coix lacryma-jobi, Colocasia esculenta, Commelina benghalensis, Commelina
diffusa, Costus speciosus, Crinum asiaticum, Curcuma amada, Curcuma longa, Curcuma
aromatica, Curculigo orchioides, Cymbopogon citratus, Cymbopogon nardus, Cynodon
dactylon, Cyperus iria, Cyperus rotundus, Dactyloctenium aegypticum, Dioscorea alata,
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Dioscorea bulbifera, Dioscorea pentaphylla, Dracaena angustifolia, Echinochloa crus-
galli, Eleusine indica, Floscopa scandens, Globba clarkei, Gloriosa superba,
Homalomena aromatica, Hedychium coronarium, Hedychium spicatum, Imperata
cylindrica, Kaempferia galanga, Kaempferia rotunda, Lasia spinosa, Lipocarpha gracilis,
Monochoria hastata, Musa balbisiana, Musa paradisiaca, Ottelia alismoides, Paspalum
conjugatum, Pothos scandens, Tacca integrifolia, Typhonium trilobatum, Zingiber
officinale, Zingiber rubens and Zingiber zerumbet.
Wild edible plants recorded in the present study:
The present study recorded 30 species of wild monocot plants of which different parts like
leaf, stem, young shoots, petiole, flower and root and root-like are used as vegetables.
(Patiri and Borah, 2007). These plants form subsidiary food of the local people.
Leaf: Colocasia esculenta, Typhonium trilobatum, Smilex zeylanica.
Fruit: Musa balbisiana, Musa velutina, Ottelia alismoides, Pandanus tectorius.
Root and root-like: Alocasia cucullata, Alocasia indica, Alpinia nigra, Bambusa pallida,
Bambusa tulda, Colocasia esculenta, Curcuma amada, Dioscorea alata, Dioscorea
bulbifera, Dioscorea pentaphylla, Maranta arundinacea, Saccharum spontaneum,
Typhonium trilobatum.
Flower: Lasia spinosa, Monochoria hastata, Typhonium trilobatum.
Petiole: Alocasia odora, Colocasia esculenta, Homalomena aromatica, Lasia spinosa.
Young shoots: Alpinia nigra, Asparagas racemosus, Bamboosa balcooa, Calamus tenuis
Commelina benghalensis, Costus speciosus, Saccharum spontaneum.
Seeds: Caryota urens, Livistona jenkinsiana, Pinanga gracilis.
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Wild relatives of the cultivated plants recorded in the present study:
167 species of important agri-horticultural crops and 320 species of their wild relatives
belonging to 116 genera and 48 families are known to have originated in India (Arora and
Nayar, 1984). The present study recorded 23 monocot species of wild relatives of
cultivated plants. They are Echinochloa colonum, Coix lacryma-jobi, Alpinia galanga,
Asparagas racemosus, Alocasia indica, Amomum subulatum, Amorphophallus bulbifer,
Colocasia esculenta, Dioscorea pentaphylla, Digitaria cruciata, Echinochloa crusgalli,
Eleusine indica, Musa velutina, Musa balbisiana, Oryza meyeriana, Paspalum
scrobiculatum, Panicum brevifolium, Pennisetum purpureum, Polytoca digitata, Polytoca
wallichiana, Saccharum spontaneum, Saccharum rufipilum, Saccharum procerum, Setaria
viridis.
Also recorded a number of monocot species which have got certain economic
potentialities. The monumental work of Borthakur (1976, 1981 and 1991), Chowdhury
(1989, 2005), Hartwell (1967-71) and a few papers authored by Sarmah et al. (2013),
Borgohain (2011), Sarma et al. (2010), Kalita et al. (2011), Das et al. (2009), published in
national and international journals were of great help in the standardization of this work.
Oil yielding: Acorus calamus, Cymbopogon citratus, Cymbopogon martini, Cymbopogon
nardus, Cocos nucifera, Elettaria cardamomum, Oryza sativa, Pandanus odorifer,
Polianthes tuberosa, Vetiveria zizanioides.
Bamboos: Bambusa arundinacea, Bambusa assamica, Bambusa balcooa, Bambusa
pallida, Bambusa tulda, Bambusa polymorpha, Bambusa garuchokua, Bambusa
rangaensis, Bambusa multiplex, Bambusa vulgaris var. vittata, Bambusa vulgaris f.
waminii, Dendrocalamus giganteus, Dendrocalamus hamiltonii, Melocanna baccifera,
Schizostachyum pergracile, Schizostachyum polymorphum.
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Beverage: Borassus flabellifer.
Broom making: Phragmites karka, Thysaenolena maxima.
Mats and Baskets: Cyperus compactus, Eichhornia crassipes, Fimbristylis dichotoma,
Fimbristylis umbellaris, Livistona jenkinsiana, Schumannianthus dichotomus.
Religious rituals: Alocasia odora, Ananas comosus, Bambusa tulda, Cocos nucifera,
Curcuma longa, Curcuma caesia, Cynodon dactylon, Kaempferia galanga, Musa
paradisiaca, Oryza sativa, Phoenix dactylifera, Saccharum officinarum, Zingiber
officinale.
Fibre yielding: Agave americana, Caryota urens, Borassus flabellifer, Furcraea foetida,
Phragmites karka, Pandanas odorifer, Yucca gloriosa.
Rope: Alpinia nigra.
Spices and condiments: Amomum aromaticum, Amomum subulatum, Amomum
dealbatum, Allium cepa, Allium sativum, Curcuma longa, Elettaria cardamomum,
Zingiber officinale.
Sugar, starches and cellulose products: Borassus flabellifer, Cocos nucifer, Colocasia
esculenta, Dioscorea alata, Maranta arundinacea, Musa sapientum, Phoenix sylvestris,
Xanthosoma sagittifolium.
Bor (1960) has listed a number of grasses which are used as fodder in different
geographical areas based on their availability.
Out of 101 species of grasses and 54 species of sedges in the present study, 53 species of
grasses and 18 species of sedges are recorded to be used as fodder.
The fodder grasses are Alloteropsis semialata, Apluda mutica, Arudinella benghalensis,
Arundinella wallichii, Axonopus compressus, Brachiaria mutica, Chrysopogon aciculatus,
Cynodon dactylon, Cyrtococcum accrescens, Dactyloctenium aegypticum, Digitaria
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cruciata, Digitaria longiflora, Dicanthium assimile, Echinochloa colonum, Echinochloa
crus-galli, Eleusine indica, Eragrostis gangetica, Eragrostis nigra, Eragrostis tenella,
Echinochloa crus-pavonis, Echinochloa stagnina, Eragrostis unioloides, Eragrostis
zeylanica, Hackelochloa granularis, Hemarthria compressa, Hemarthria protensa,
Heteropogon contortus, Heteropogon contortus, Hymenachne assamica, Isachne globosa,
Leersia hexandra, Leptochloa chinensis, Oplismenus burmanii, Oplismenus compositus,
Oryza meyeriana, Panicum auritum, Panicum brevifolium, Panicum maximum, Panicum
paludosum, Paspaladium flavidum, Paspaladium punctatum, Paspalum conjugatum,
Paspalum scrobiculatum, Pogonotherum crinitum, Polytoca digitata, Panicum montanum,
Pogonotherum paniceum, Pennisetum purpureum, Rottboellia cochinchinensis,
Saccharum procerum, Sporobolus diander, Sporobolus diander and Sorghum nitidum.
The fodder sedges are Actinoscirpus grossus, Carex cruciata, Cyperus halpan L.,
Cyperus brevifolius, Cyperus compressus, Cyperus digitatus, Cyperus iria, Cyperus
pilosus, Cyperus rotundus, Cyperus tenuispica, Eleocharis acutangula, Fimbristylis
aestivalis, Fimbristylis littoralis, Fimbristylis miliacea, Pycreus flavidus,
Schonoeplectiella articulata, Schonoeplectiella juncoides and Scleria terrestris.
6.6 Conservation strategies:
The floristic wealth of the region is under serious threat due to various reasons like
explosive growth of concrete buildings, construction of roads, clearance of forests for
various developmental activities, expansion of agriculture in forest lands, over-
exploitation of forest resources without any consideration for their sustainability,
introduction of alien species and failure of legal protection. The exponential growth, in
both human as well as cattle population, has resulted in an increasing demand and supply
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of natural resources. As a result of which, more forests areas are being cleared for
agricultural practices and this may create havoc to those plants which have very limited
distribution in the world. The presence of various rare, endemic, threatened and
endangered plants in the district demand a special attention for preservation in their wild
state. Proper policies/strategies must be adapted for conservation and management of
biodiversity to prevent the extinction or decline of species particularly the endemic ones.
It is the right time to draw the attention of the government authorities, NGO’s and
common people towards the conservation of biodiversity immediate task must be devised
and enforced in a time bound programme for saving plants as well as habitats of biological
resources.
Action plan for conservation, therefore, must be directed to:
• Identification of unique, rare and endangered species
• Control of over exploitation through CITES and other agencies
• Restriction on introduction of exotic species without adequate investigation
• Plantation in degraded land through social forestry or other voluntary programmes
• Controlling enforcement grazing, illicit felling
• Creating environmental awareness among people and promoting eco-friendly
alternatives to reduce pressure on environment and forests
• Introduction of scientific methods/tools for rapid monitoring and identification of
threats to biodiversity
• Encouraging research scholars to work on forestry, wildlife and biodiversity.
The challenge for the global community is not to save biodiversity, “Treasure of Nature”,
for its own sake, but to ensure that biodiversity is used sustainably and equitably for
human development.
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Chapter 7: SUMMARY
1. The present study on ‘Monocot flora of erstwhile Kamrup District of Assam with
special reference to grasses and sedges’ was undertaken during 2007-2011 to record the
floristic wealth of erstwhile Kamrup district of Assam. The study also includes a brief
account on the geology, topography, climate and soil of the study area which have great
impact on the growth and development of the vegetation.
2. Reviewed literature includes past botanical explorations of India, N. E. India, Assam
and Kamrup district.
5. Collected plant specimen were deposited as herbarium species in the Herbarium of
Botany Department, Gauhati University (GUBH).
3. The study undertaken was accomplished by carefully planning field and herbarium
works so as to cover all the parts of the study area in all the seasons. During field work
information on vernacular names, habitat, flowering and fruiting time etc. were recorded.
Photographs on habits, habitats of one or the other species were also taken.
6. Morphological characters of the collected plant specimen along with floral characters
studied through dissection were recorded.
4. After preliminary identification by comparing with available literature, the
identifications of the specimens were confirmed by consulting the herbarium materials of
Cotton College Botany Hernbarium (CCBH) and BSI, Shillong (ASSAM).
8. A total of 371 species belonging to 193 genera included in 31 families is enumerated.
Artificial keys for genera and species are like-wise given under their respective families
and genera when the number of genera and species are more than one.
9. Analytical drawings of 39 species are provided.
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10. For each and every species, as far as possible, the accepted names are included with
their original citations. Citation of various important references are given. As far as
possible published vernacular names are provided which is followed by a brief description
of the species and habitat.
11. 121 ornamental plants, 70 plants with medicinal value, 32 wild edible plants, 65 plants
with various economic potentialities, 23 species of wild relatives of cultivated plants, 53
fodder grasses and 18 fodder sedges are recorded.
12. 16 endemic taxa and 26 RET taxa are also recorded.
