Data are the pooled means of three estimates each over two years ±standard deviation. 'p-value' denotes the significance of difference between the means by one way ANOVA statistics. a The values

\* **Cul**: *Cassia uniflora* Mill.non Spreng ; **Snl**: *Synedrella nodiflora*(L) Gaertn; **Alt**: *Alternanthera tenella* Colla; **Eug**: *Euphorbia geniculata* Orteg.; **Ach**: *Achyranthes aspera* L.; **Bod**: *Boerhaavia erecta* L.; **Bln**: *Blainvillea acmella* L.; **Aca**: *Acalypha ciliata* Forsk.; **Tum:** *Triumfetta rhomboidea* Jacq.; **Cab**: *Cassia absus* L.; **Cfl:** *Cassia obtusifolia* L.; **Bdn**: *Bidens biternata* Lour.; **Raw:** *Rauwolfia tetraphylla* L.; **Opl:** *Oplismenus compositus* P.Beauv.

The invasive and native weeds showed considerable variations in reproductive characters (Table 3 a). The type of inflorescence in majority of the weeds studied was mostly head,

4 g ± 0.24 15 f ± 0.9 11.8 fg

8 c ± 0.4 31a ±1.5 14.9 e ±

III Leaf area cm2

20.41 d ± 0.81

0.74

12.8 ef ± 0.89

18.41 d ± 0.55

± 0.70

12.2 fg ± 0.73

13 ef ± 0.52

10.5 g ± 0.73

33.66 c ± 1.00

18.5 d ± 0.92

> 45 a ± 1.35

33.1 c ± 1.98

42.66 b ± 2.98

3.5 h ± 0.14

Fresh biomass / plt. g

> 36.3 d ± 1.45

15.68 g ± 0.78

21.5 f ± 1.50

19.06 f ± 0.57

31.13 e ± 1.86

34.72 d ± 2.08

12.33 hi ± 0.49

> 9.33 i ± 0.65

88.33 b ± 2.64

11.66 hi ± 0.58

91.66 a ± 2.74

12.9 gh ± 0.77

> 56.66 c ±3.96

5.35 j ± 0.21

Dry biomass / plt. g

> 12.4± 0.49

4. 1± 0.20

8.3± 0.58

4.6± 0.13

10.7± 0.64

10.2± 0.61

1.43± 0.05

1.75± 0.12

3.1± 0.09

3.02± 0.15

17.43± 0.52

2.35± 0.14

9.5± 0.66

0.89 ± 0.03

Fresh biomass / m2 g

2316.2 b ± 92.64

282.42 f ± 14.12

356.84 e ± 24.98

114.36 g ± 3.43

108.39 g ± 6.50

347.2 e ± 20.83

579.51 c ± 23.18

171.67 g ± 12.01

2473.24 a ± 74.19

139.92 g ± 6.99

366.64 e ± 10.99

472.14 d ± 28.32

396.62 e ±27.76

112.35 g ± 4.49

\*Weed spp.

Plt. Ht. cm.

Cul 104.66 a± 4.18

Snl 63.66 e ± 3.18

Alt 91 b ± 6.37

Eug 73.66 c ± 2.20

Bod 46.33 g ± 2.77

Ach 96.33 b ± 5.77

Bln 66 de ± 2.64

Aca 49.66 f ± 3.47

Tum 103.66 a± 3.10

Cab 52.26 fg± 2.61

Bdn 55.23 f ± 3.31

Raw 63 e ± 4.41

Opl 23.12 h ± 0.92

71.83 cd± 2.15

Cfl

Root length cm.

17.66 c ± 0.70

17 c ± 0.85

22.66 a ± 1.58

13.3 d ± 0.39

8.16 g ± 0.48

> 20 b ± 1.2

5.5 h ± 0.22

4.5 hi ± 0.31

9.66 f ± 0.28

11.4 e ± 0.57

13.16 d

7.96 g ±

20.76 b

3.2.i ± 0.12

No. of Branches/plt.

7 d ± 0.28 18 e ±

9 b ± 0.63 28 b ±

3 h ± 0.09 10 g ±

11 a ± 0.66 24 d ±

6.33 e ± 0.25 7.33 h ±

0 i ± 0 26 c ±

11 a ± 0.33 25 cd ±

8.33 c ± 0.41 7.33 h ±

0 i ± 0 10 g ±

followed by different letters differ significantly by Duncan's multiple range test at p=0.05.

± 0.39 6.66 de ± 0.19 14.66 f ±

0.47 8.33 c ± 0.49 9.66 g ±

± 1.45 5.33 f ±0.37 20.33 e

Table 2. Morphological features of invasive and native weeds

**4.5 Reproductive capabilities of invasive and native weeds** 

spike or cyme. Only in *Euphorbia,* it was cyathium, and in *Oplismenus* it was panicle. In almost all the weeds the inflorescence was axillary, but only in *Achyranthes* and *Cassia absus*, it was terminal.

For the number of inflorescences per plant *Triumfetta,* was at first rank, which was followed sequentially by *Alternanthera, Synedrella* and *Cassia uniflora.* The weed species like *Blainvillea*, *Acalypha* and *Achyranthes* were at medium position, while the least number was noted in *Oplismenus.* 

The number of flowers, florets and flowerbuds per inflorescence was also a diagnostic feature for all the weeds. *Acalypha* was having highest number of male and female flowers together, whilst *Achyranthes* was following it (Table 3a). *Oplismenus* was in third position and it was followed by *Synedrella*. Remaining weeds had very few numbers of flowers**/** florets**/** flowerbuds and the lowest number of flowers was in *Triumfetta.*

The number of fruits per inflorescence is very important reproductive character which was in the order of –

```
Snl > Ach > Bdn > Alt > Tum > Bln > Aca > Cul > Cfl > Cab > Opl > Eug > Raw (Table 3b).
```
The number of seeds per plant was not showing the same order as that of number of fruits (Table 3b). This was due to the number of seeds per fruit, which is again a specific and variable character for a particular plant. The descending sequence for number of seeds per plant was:


Cfl > Snl > Ach > Cul > Aca > Bdn > Tum > Cab > Alt > Bod > Bln > Eug > Opl > Raw.

Table 3. (a) Reproductive features of invasive and native weeds

Morphophysiological Investigations in Some Dominant Alien Invasive Weeds 29

The role of reproductive capacity of weeds from arid zones was carried out by Sen (1981) and Kanchan and Jayachandra (1977) for *Parthenium hysterophorus*. The seed output and other propagules was studied by Stevens (1957) for different weed species. Many researchers like Young (1991), Norris (1992), Huang Hua et al. (2007) and Khanh et al. (2009) had studied the reproductive biology of Russian thistle, barnyardgrass, *Solidago canadensis* and *Bidens pilosa* respectively. Hu and Wang (2001) studied the reproduction of two weedy vines. Qiaoying Zhang et al. (2009) had investigated the allelopathic potential of reproductive organs (flowers and fruits) of *Lantana camara* and explained their role in

The reproductive characters are the probable indicators of plants' invasiveness and aggressiveness in the ecosystem. Not only this, but they are also the factors deciding their density and abundance. Dekker (2005) had also opined similarly indicating the role of reproductive features in plant invasion. Bhan et al. (1976) also emphasized on the role of reproductive behavior of *Phalaris minor* in its dominance and invasion. In the present study also, the comparison made on the basis of morphological and reproductive characters between invasive and native weeds revealed that the selected invasive weeds were superior in all the above-mentioned features, reflecting on their dominance over natives in the campus of Pune University. Friedman and Waller (1983) also stated that the seeds of plants act as allelopathic agents, releasing the different types of allelochemicals in their

The results shown in Figure 1 revealed that amongst invasive weeds *Cassia uniflora* and *Synedrella* had higher chlorophyll a, b and total chlorophyll contents, followed by *Alternanthera.* Amongst invasive weeds *Bidens* and *Blainvillea* are at par for chlorophyll contents. Amongst the natives *Triumfetta* was following *Achyranthes* for photosynthetic pigments. Remaining invasive and native weeds were at intermediate state for the contents of photosynthetic pigments. Whilst, *Oplismenus* and *Rauwolfia* had shown the lowest chlorophyll contents. The invasive weeds like *Cassia uniflora, Synedrella* and *Alternanthera* 

The results recorded on photosynthetic pigments in different invasive and native weeds were corroborating with that of photosynthetic rate and other gas exchange parameters (Table 4 and Figure 1). Ghayal et al. (2009) have quantified the photosynthetic pigments in different invasive, native, aquatic as well as terrestrial weeds. Pawar (2004), Jadhav (2006), Castillo et al. (2007), Vaidya (2009) have quantified the photosynthetic pigments in different invasive, native, aquatic as well as terrestrial weeds. Wang et al*.* (2004) also recorded significant contents of chlorophylls and better photosynthetic rate in *Eupatorium.* Bhalerao (2003) had made similar observations regarding photosynthetic pigments in fern species like

Photosynthetic pigments are the master molecules in carbon assimilation process, which govern photosynthetic efficiency. Sampietro et al. (2007) explained that the growth, development, dominance and allelopathic potential of any plant species mostly depend on its physiological, biochemical and enzymological characteristics. The growth, development, dominance and allelopathic potential of any plant species mostly depend on its physiological, biochemical and enzymological characteristics. The allelochemicals in it are also important along with above aspects. The amount of photosynthetic pigments usually correlates with photosynthetic rate, which is directly or indirectly reflected into

had shown maximum amount of chlorophyll a, chlorophyll b and total chlorophylls.

successful invasion, encroachment and dominance of it.

surrounding environment and which help to establish their dominance.

**4.6 Light harvesting components in invasive and native weeds** 

*Tectaria* and *Pteridium* from Mahabaleshwar area.

The results on reproductive capacity of invasive and native weeds revealed that the highest reproductive capacity was recorded in *Cassia obtusifolia,* which was followed by *Synedrella.*  While *Achyranthes* and *Cassia uniflora* were on the third rank*.* The least reproductive capacity was reported in *Boerhaavia* (Table 3b).


Table 3. (b) Reproductive features of invasive and native weeds

Fig. 1. Photosynthetic pigments in the invasive and native weeds

The role of reproductive capacity of weeds from arid zones was carried out by Sen (1981). Many researchers like Khanh et al. (2009) had studied the reproductive biology of Russian thistle, barnyardgrass, *Solidago canadensis* and *Bidens pilosa* respectively. Some have investigated the allelopathic potential of reproductive organs (flowers and fruits) of *Lantana camara* and explained their role in successful invasion, encroachment and dominance of it.

The results on reproductive capacity of invasive and native weeds revealed that the highest reproductive capacity was recorded in *Cassia obtusifolia,* which was followed by *Synedrella.*  While *Achyranthes* and *Cassia uniflora* were on the third rank*.* The least reproductive capacity

> seeds / fruit

Cul 9 2736 f ± 109.44 8 21888 d ± 875.52 18604 c ± 744.16 Snl 21 26460 a ± 1323 1 26460 b ± 1323 23814 b ± 1190.7 Alt 9 6075 d ± 425.25 1 6075 gh ± 425.25 3037.5 fg ± 212.62 Eug 8 576 h ± 17.28 3 1728 k ± 51.84 691.2 h ± 20.73 Bod 13 5070 e ± 304.2 1 5070 hi ± 304.2 2028 g ± 121.68 Ach 32 24192 b ± 1451.52 1 24192 c ± 1451.52 19353.6 c ± 1161.21 Bln 13 4280.77 e ± 171.23 1 4280.77 ij ± 171.23 2996.539 fg ± 119.86 Aca 1 4100.9 e ± 287.063 3 12302.7 e ± 861.18 6679.89 e ± 467.59 Tum 12 4320 e ± 129.6 2 8640 f ± 259.2 3247.72 f ± 97.43 Cab 14 1697.36 g ± 84.86 4 6789.44 g ± 339.472 3394.72 f ± 169.73 Cfl 14 1915.91 fg ± 57.47 32 62266.9 a ± 1868.007 28020.11 a ± 840.60 Bdn 37 9653.14 c ± 579.18 1 9653.14 f ± 579.18 8205.05 d ± 492.30 Raw 7 495.65 h ± 34.6955 2 991.309 k ± 69.39 7183.4 e ± 502.83 Opl 24 1152 gh ± 46.08 1 1152 k ± 46.08 6220.8 e ± 248.83 p**=** <0.001 <0.001 <0.001

**<sup>e</sup> <sup>e</sup> de de <sup>e</sup> de**

**Aca**

The role of reproductive capacity of weeds from arid zones was carried out by Sen (1981). Many researchers like Khanh et al. (2009) had studied the reproductive biology of Russian thistle, barnyardgrass, *Solidago canadensis* and *Bidens pilosa* respectively. Some have investigated the allelopathic potential of reproductive organs (flowers and fruits) of *Lantana camara* and explained their role in successful invasion, encroachment and

**Weeds**

**g**

**ef**

**Bln**

**f**

**g**

**Bod**

**g**

**g g gh gh**

**Cab**

**f**

**Tum**

No. of seeds **/** plant

Reproductive Capacity

**ef f**

**Raw**

**gh h**

**h i**

**Chl-a Chl-b TChl**

**Opl**

**cd**

**<sup>g</sup> <sup>h</sup>**

**Cfl**

**ef**

**Bdn**

**ef**

was reported in *Boerhaavia* (Table 3b).

No. of fruits / plant No. of

Table 3. (b) Reproductive features of invasive and native weeds

**d e**

**Ach**

Fig. 1. Photosynthetic pigments in the invasive and native weeds

**e**

**Eug**

**d**

**<sup>b</sup> bc <sup>b</sup> <sup>a</sup> <sup>a</sup>**

**<sup>b</sup> <sup>a</sup>**

dominance of it.

**mg g-1**

**Cul**

**Snl**

**a**

**b**

**c**

**Alt**

**c**

No. of fruits / inflo.

Weed species The role of reproductive capacity of weeds from arid zones was carried out by Sen (1981) and Kanchan and Jayachandra (1977) for *Parthenium hysterophorus*. The seed output and other propagules was studied by Stevens (1957) for different weed species. Many researchers like Young (1991), Norris (1992), Huang Hua et al. (2007) and Khanh et al. (2009) had studied the reproductive biology of Russian thistle, barnyardgrass, *Solidago canadensis* and *Bidens pilosa* respectively. Hu and Wang (2001) studied the reproduction of two weedy vines. Qiaoying Zhang et al. (2009) had investigated the allelopathic potential of reproductive organs (flowers and fruits) of *Lantana camara* and explained their role in successful invasion, encroachment and dominance of it.

The reproductive characters are the probable indicators of plants' invasiveness and aggressiveness in the ecosystem. Not only this, but they are also the factors deciding their density and abundance. Dekker (2005) had also opined similarly indicating the role of reproductive features in plant invasion. Bhan et al. (1976) also emphasized on the role of reproductive behavior of *Phalaris minor* in its dominance and invasion. In the present study also, the comparison made on the basis of morphological and reproductive characters between invasive and native weeds revealed that the selected invasive weeds were superior in all the above-mentioned features, reflecting on their dominance over natives in the campus of Pune University. Friedman and Waller (1983) also stated that the seeds of plants act as allelopathic agents, releasing the different types of allelochemicals in their surrounding environment and which help to establish their dominance.

### **4.6 Light harvesting components in invasive and native weeds**

The results shown in Figure 1 revealed that amongst invasive weeds *Cassia uniflora* and *Synedrella* had higher chlorophyll a, b and total chlorophyll contents, followed by *Alternanthera.* Amongst invasive weeds *Bidens* and *Blainvillea* are at par for chlorophyll contents. Amongst the natives *Triumfetta* was following *Achyranthes* for photosynthetic pigments. Remaining invasive and native weeds were at intermediate state for the contents of photosynthetic pigments. Whilst, *Oplismenus* and *Rauwolfia* had shown the lowest chlorophyll contents. The invasive weeds like *Cassia uniflora, Synedrella* and *Alternanthera*  had shown maximum amount of chlorophyll a, chlorophyll b and total chlorophylls.

The results recorded on photosynthetic pigments in different invasive and native weeds were corroborating with that of photosynthetic rate and other gas exchange parameters (Table 4 and Figure 1). Ghayal et al. (2009) have quantified the photosynthetic pigments in different invasive, native, aquatic as well as terrestrial weeds. Pawar (2004), Jadhav (2006), Castillo et al. (2007), Vaidya (2009) have quantified the photosynthetic pigments in different invasive, native, aquatic as well as terrestrial weeds. Wang et al*.* (2004) also recorded significant contents of chlorophylls and better photosynthetic rate in *Eupatorium.* Bhalerao (2003) had made similar observations regarding photosynthetic pigments in fern species like *Tectaria* and *Pteridium* from Mahabaleshwar area.

Photosynthetic pigments are the master molecules in carbon assimilation process, which govern photosynthetic efficiency. Sampietro et al. (2007) explained that the growth, development, dominance and allelopathic potential of any plant species mostly depend on its physiological, biochemical and enzymological characteristics. The growth, development, dominance and allelopathic potential of any plant species mostly depend on its physiological, biochemical and enzymological characteristics. The allelochemicals in it are also important along with above aspects. The amount of photosynthetic pigments usually correlates with photosynthetic rate, which is directly or indirectly reflected into

Morphophysiological Investigations in Some Dominant Alien Invasive Weeds 31

amongst the invasive and native weed species investigated. Funk and Vitousek (2007) have reported the positive co-relation with leaf traits and WUE in some weeds. Blicker et al. (2003) had also reported higher water use efficiency in the invasive weed *Centaurea maculosa*

> III leaf area cm2

> > ± 0.82

0.75

± 0.90

0.55

± 0.73

± 0.71

± 0.52

1.01

1.99

2.99

0.14
