**4. Analysis of the Chilean grass diversity**

To analyze the diversity of the family Poaceae in Chile, a database was prepared based on the collections of the herbaria of University of Concepción (CONC), National Museum of Natural History (SGO) and specimens cited in Tropicos database (tropicos.org), and taxonomic literature [Acevedo de Vargas (1959, *Cortaderia* Stapf); Baeza (1996, *Danthonia* DC., *Rytidosperma* Steud.); Cialdella & Arriaga (1998, *Piptochaetium* J. Presl); Cialdella & Giussani (2002, *Piptochaetium*); De Paula (1975, *Anthoxanthum* L. under *Hierochlöe* R.Br.); Finot et al. (2005, *Trisetum* Pers.); Matthei (1965, *Nassella* (Trin.) E. Desv. under *Stipa* L.; 1975, *Briza* L.; 1982, *Festuca*; 1986, *Bromus* L.; 1987ª, *Aristida* L., 1987b; *Panicum* L.); Muñoz-Schick (1985, *Melica* L.; 1990, *Nassella*); Nicora (1998, *Eragrostis* Wolf); Rúgolo de Agrasar (1978, 2006, *Deyeuxia* Kunth; 1982, *Bromidium* Nees et Meyen; 1999, *Corynephorus* P. Beauv.); Rúgolo de Agrasar & Molina (1997, *Agrostis* L.)]; Rúgolo de Agrasar et al. (2009, *Danthonia*); Soreng & Gillespie (2007, *Nicoraepoa*); Soreng & Peterson (2008, *Poa*)]. A total of 13.924 records were included in the database, including the name of the species, subfamily, tribe, subtribe, geographical origin (native, introduced, endemic), collector, latitude, longitude, altitude, locality, date of collection, herbarium, and herbarium number. A checklist of the species based in the database, the Catalogue of the New World Grasses (Judziewicz et al., 2000; Peterson et al., 2001; Soreng et al., 2003; Zuloaga et al., 2003, available online at http://www.Tropicos.org) and the Catálogo de las plantas vasculares del Cono Sur (Zuloaga et al., 2008, available online at http://www2.darwin.edu.ar) was prepared. Recent taxonomic treatments of Chloridoideae (Peterson et al., 2007; Peterson et al., 2010), Danthonioideae (Linder et al., 2010), Panicoideae (Sánchez-Ken & Clark, 2010), *Avenella*, *Deschampsia, Vahlodea* (Chiapella & Zuloaga, 2010), *Bromus* (Planchuelo, 2010), *Cenchrus* (Chemisquy et al., 2010), *Deyeuxia* (Rúgolo de Agrasar, 2006), *Digitaria* (Vega et al., 2009) and *Trisetum* (Finot, 2010), were followed to update the nomenclature and the classification of the species. Lists of the species of the family Poaceae growing in Chile have been published for different regions (Arroyo et al., 1989, 1990, 1992, 1998; Baeza et al., 1999, 2002, 2007; Finot et al., 2009; Kunkel, 1968; Matthei et al., 1993; Reiche, 1903; Rodríguez et al., 2008a, 2008b; Rundel et al., 1996) or for all the country (Muñoz, 1941; Marticorena & Quezada, 1985; Zuloaga et al., 2008).

Many species of Chilean grasses were collected and described early in the nineteenth century. The collection of grass specimens began at a fairly early stage of the knowledge of the diversity of the Chilean flora, in the early nineteenth century, with the collections made by Eduard Poeppig, Carlo Bertero, Rodulfo Amando and Federico Philippi, and Claudio Gay. In this period, Emile Desvaux published one of the first complete treatments of the Chilean grasses in Gay's "*Historia Física y Política de Chile*" (Desvaux, 1854), including 22 beautiful illustrations of native and endemic Chilean grasses, in Gay's Atlas. In the early twentieth century, new collections were made by Karl Reiche, Félix Jaffuel, Víctor Baeza, Franz Neger, Ernesto Barros, Atanasio Hollermayer, Hugo Gunckel, Erich Werdermann, Karl Junge, and Gilberto Montero, among others. Nonetheless, the number of specimens and, as a result, the number of species collected in the first 10 decades (1828-1917) is quite small (Fig. 2). In the early twentieth century only about 20% of the currently known grass flora had been collected. Since 1918 the collection effort was significantly increased; among 544 and 2063 specimens per decade were collected. These new collections allowed recording more than 430 new species. In order to compare the collection effort in the fifteen political

To analyze the diversity of the family Poaceae in Chile, a database was prepared based on the collections of the herbaria of University of Concepción (CONC), National Museum of Natural History (SGO) and specimens cited in Tropicos database (tropicos.org), and taxonomic literature [Acevedo de Vargas (1959, *Cortaderia* Stapf); Baeza (1996, *Danthonia* DC., *Rytidosperma* Steud.); Cialdella & Arriaga (1998, *Piptochaetium* J. Presl); Cialdella & Giussani (2002, *Piptochaetium*); De Paula (1975, *Anthoxanthum* L. under *Hierochlöe* R.Br.); Finot et al. (2005, *Trisetum* Pers.); Matthei (1965, *Nassella* (Trin.) E. Desv. under *Stipa* L.; 1975, *Briza* L.; 1982, *Festuca*; 1986, *Bromus* L.; 1987ª, *Aristida* L., 1987b; *Panicum* L.); Muñoz-Schick (1985, *Melica* L.; 1990, *Nassella*); Nicora (1998, *Eragrostis* Wolf); Rúgolo de Agrasar (1978, 2006, *Deyeuxia* Kunth; 1982, *Bromidium* Nees et Meyen; 1999, *Corynephorus* P. Beauv.); Rúgolo de Agrasar & Molina (1997, *Agrostis* L.)]; Rúgolo de Agrasar et al. (2009, *Danthonia*); Soreng & Gillespie (2007, *Nicoraepoa*); Soreng & Peterson (2008, *Poa*)]. A total of 13.924 records were included in the database, including the name of the species, subfamily, tribe, subtribe, geographical origin (native, introduced, endemic), collector, latitude, longitude, altitude, locality, date of collection, herbarium, and herbarium number. A checklist of the species based in the database, the Catalogue of the New World Grasses (Judziewicz et al., 2000; Peterson et al., 2001; Soreng et al., 2003; Zuloaga et al., 2003, available online at http://www.Tropicos.org) and the Catálogo de las plantas vasculares del Cono Sur (Zuloaga et al., 2008, available online at http://www2.darwin.edu.ar) was prepared. Recent taxonomic treatments of Chloridoideae (Peterson et al., 2007; Peterson et al., 2010), Danthonioideae (Linder et al., 2010), Panicoideae (Sánchez-Ken & Clark, 2010), *Avenella*, *Deschampsia, Vahlodea* (Chiapella & Zuloaga, 2010), *Bromus* (Planchuelo, 2010), *Cenchrus* (Chemisquy et al., 2010), *Deyeuxia* (Rúgolo de Agrasar, 2006), *Digitaria* (Vega et al., 2009) and *Trisetum* (Finot, 2010), were followed to update the nomenclature and the classification of the species. Lists of the species of the family Poaceae growing in Chile have been published for different regions (Arroyo et al., 1989, 1990, 1992, 1998; Baeza et al., 1999, 2002, 2007; Finot et al., 2009; Kunkel, 1968; Matthei et al., 1993; Reiche, 1903; Rodríguez et al., 2008a, 2008b; Rundel et al., 1996) or for all the country (Muñoz, 1941; Marticorena & Quezada, 1985;

Many species of Chilean grasses were collected and described early in the nineteenth century. The collection of grass specimens began at a fairly early stage of the knowledge of the diversity of the Chilean flora, in the early nineteenth century, with the collections made by Eduard Poeppig, Carlo Bertero, Rodulfo Amando and Federico Philippi, and Claudio Gay. In this period, Emile Desvaux published one of the first complete treatments of the Chilean grasses in Gay's "*Historia Física y Política de Chile*" (Desvaux, 1854), including 22 beautiful illustrations of native and endemic Chilean grasses, in Gay's Atlas. In the early twentieth century, new collections were made by Karl Reiche, Félix Jaffuel, Víctor Baeza, Franz Neger, Ernesto Barros, Atanasio Hollermayer, Hugo Gunckel, Erich Werdermann, Karl Junge, and Gilberto Montero, among others. Nonetheless, the number of specimens and, as a result, the number of species collected in the first 10 decades (1828-1917) is quite small (Fig. 2). In the early twentieth century only about 20% of the currently known grass flora had been collected. Since 1918 the collection effort was significantly increased; among 544 and 2063 specimens per decade were collected. These new collections allowed recording more than 430 new species. In order to compare the collection effort in the fifteen political

**4. Analysis of the Chilean grass diversity** 

Zuloaga et al., 2008).

regions in which the country is divided (Table 1), we calculated the collection index (Squeo et al., 1998):


CI = Number of species/Number of collections (1)

Table 1. Poaceae diversity of Chile at national and regional level. NCO = number of collected specimens, CI = collection index, Regions: AP = Arica and Parinacota, TA = Tarapacá, AN = Antofagasta, AT = Atacama, CO = Coquimbo, VA = Valparaíso, ME = Metropolitan, OH = O'Higgins, MA = Maule, BB = Bío-Bío, AR = Araucanía, LR = Los Ríos, LL = Los Lagos, AY = Aysén, MG = Magallanes and Antarctica Chilena. \*Mean value of ICE, Chao2, Jacknife1, Jacknife2, Bootstrap and Michaelis-Menten estimators.

The collection index takes values ranging from 1 to near zero. Value 1 indicates poor collection effort while values near to 0 indicate that the region is over-collected (Squeo et al., 1998). Collections are not uniformly distributed along the country; on the contrary, some regions have been collected more or less intensely (e.g. Bío-Bío, Metropolitan, Magallanes, Araucanía, Valparaíso), while others regions (e.g. O'Higgins, Tarapacá and Aysén) have been weakly collected (Table 1, Fig. 5). The species accumulation curves allow the estimation of species richness from a sample and to compare the species richness of different areas. The accumulation curve for the country together with the curves of the five species richness estimators are shown in Fig. 3. The accumulation curve for the all country tends to be asymptotic (Fig. 3) and the mean number of estimated taxa (Table 1) indicated that our database included about 85.5% of the taxa expected to be found in Chile. There are about 70 taxa not yet collected, nevertheless, these indicators show that the overall knowledge of

Systematic Diversity of the Family Poaceae (Gramineae) in Chile 81

4

5

Specimens Species

6

7

8 9

Fig. 2. Accumulated number of specimens and accumulated number of species collected in

In Antofagasta there were 125 taxa, and a greater collection effort (Table 1); in comparison with the other two regions of "Norte Grande", in Antofagasta reside a greater number of endemic species: *Anatherostipa venusta*, *Festuca morenensis*, *F. tunicata*, *F. werdermannii*, *Jarava* 

In the near north, we found two regions: Atacama (AT) and Coquimbo (CO), located between the hyper-arid region of Antofagasta and the more fertile region of Central Chile, between the rivers Copiapó and Aconcagua. In Atacama, only 106 taxa were recognized, of which 58 are native or endemic, while other six species were included in the Catalogue of the vascular flora of Atacama (Squeo et al. 2008). Nevertheless, the collection index shows a relatively small collection effort for grasses in Atacama (Table 1). Endemic species in Atacama are *Festuca werdermannii*, *Jarava tortuosa*, *Nassella duriuscula*, *N. pungens*, and *Poa* 

In Coquimbo there is an increase of the taxonomic biodiversity, coupled with an increased collection effort. The number of taxa reaches 167, which corresponds to the highest for Poaceae in northern Chile. According to the Catalogue of the vascular flora of Coquimbo (Marticorena et al., 2001), the flora of this region (native and naturalized) includes 1727 species of which nearly 9% belong to Poaceae. An analysis of the biodiversity of Coquimbo (Squeo et al., 2001) mentions 104 species of Poaceae, the second most diverse family after Asteraceae in Coquimbo. An increase in the number of endemic grasses also takes place (Table 1). There are 26 endemic grasses belonging to 12 genera. The high degree of endemic species of Poaceae coincides with the high degree of endemism present in this region (53.5% of the vascular flora is endemic to Chile) (Squeo et al., 2001). The subfamily Bambusoideae has its septentrional limit of distribution in the region of Coquimbo. In Fray Jorge, there are 11 species of Poaceae, including *Chusquea cumingii* (Arancio et al., 2004), which represents

Central Chile includes the regions of Valparaíso, Metropolitana, O'Higgins, Maule and Bío-Bío, approximately between 32° and 36°S. The high degree of anthropic pressure in central Chile is reflected in the greatest number of introduced species (approx. 10-16% of grasses are adventives). Due to the high percentage of endemic species, the high percentage of introduced species is disquieting as most of them are invasive weeds (Matthei, 1995). As has

1

10

*matthei*, *J. tortuosa*, *Nassella pungens*, *Poa paposana*, and *Polypogon linearis*.

the northernmost record of subfamily Bambusoideae in Chile.

11 12

13

Chile in the 18 decades between 1828 and 2007.

*paposana*.

14

15

16

17 18 2 3

Fig. 1. Grassland communities in Aysén, Chile (R. Wilckens & F. Silva).

Chilean grasses is good enough. On the other hand, the species accumulation curves at regional level (Fig. 4) show the number of taxa collected as a function of sampling effort (time) for each political region. Figure 4 show that the regions with lower richness are Tarapacá (TA), O'Higgins (OH), Atacama (AT) and Aysén (AY), while those with higher species richness are Bío-Bío (BB), Metropolitan (ME), Araucanía (AR) and Valparaíso (VA). According to Table 1, only 55% of the expected taxa for the region of O´Higgins are represented in the botanical collections.

The species richness of Poaceae along the country is shown in Fig. 5. The regions located in northern Chile, Arica and Parinacota (AP), Tarapacá (TA), and Antofagasta (AN), known collectively as "Norte Grande" (Far North), and the regions of Atacama and Coquimbo, known as "Norte Chico" (Near North), are characterized by its desert climate because of the presence of the Atacama Desert. In the Far North, the diversity of grasses reaches relatively low values when compared with the regions of central and southern Chile.

In Arica and Parinacota, there are 109 taxa (68% non-endemic native, 5.94% endemic, and 15.84% introduced), belonging to six subfamilies (Bambusoideae and Ehrhartoideae are absent in northern Chile), and 42 genera. The taxonomic biodiversity is higher than in the other regions of the Far North. Six endemic species were detected in Arica and Parinacota: *Anatherostipa venusta*, *Bromus gunckelii*, *Cynodon nitidus*, *Festuca panda*, *Nassella pungens*, and *Trisetum johnstonii* subsp. *mattheii*, the latter species is an endemic at regional level.

In Tarapacá there were 73 taxa in six subfamilies and 36 genera; however, the collection effort is lower than in the adjacent regions; four species endemic to Chile were present in this region: *Anatherostipa venusta*, *Bromus gunckelii*, *Cynodon nitidus*, and *Polypogon linearis* Trin.

Fig. 1. Grassland communities in Aysén, Chile (R. Wilckens & F. Silva).

low values when compared with the regions of central and southern Chile.

*Trisetum johnstonii* subsp. *mattheii*, the latter species is an endemic at regional level.

represented in the botanical collections.

Trin.

Chilean grasses is good enough. On the other hand, the species accumulation curves at regional level (Fig. 4) show the number of taxa collected as a function of sampling effort (time) for each political region. Figure 4 show that the regions with lower richness are Tarapacá (TA), O'Higgins (OH), Atacama (AT) and Aysén (AY), while those with higher species richness are Bío-Bío (BB), Metropolitan (ME), Araucanía (AR) and Valparaíso (VA). According to Table 1, only 55% of the expected taxa for the region of O´Higgins are

The species richness of Poaceae along the country is shown in Fig. 5. The regions located in northern Chile, Arica and Parinacota (AP), Tarapacá (TA), and Antofagasta (AN), known collectively as "Norte Grande" (Far North), and the regions of Atacama and Coquimbo, known as "Norte Chico" (Near North), are characterized by its desert climate because of the presence of the Atacama Desert. In the Far North, the diversity of grasses reaches relatively

In Arica and Parinacota, there are 109 taxa (68% non-endemic native, 5.94% endemic, and 15.84% introduced), belonging to six subfamilies (Bambusoideae and Ehrhartoideae are absent in northern Chile), and 42 genera. The taxonomic biodiversity is higher than in the other regions of the Far North. Six endemic species were detected in Arica and Parinacota: *Anatherostipa venusta*, *Bromus gunckelii*, *Cynodon nitidus*, *Festuca panda*, *Nassella pungens*, and

In Tarapacá there were 73 taxa in six subfamilies and 36 genera; however, the collection effort is lower than in the adjacent regions; four species endemic to Chile were present in this region: *Anatherostipa venusta*, *Bromus gunckelii*, *Cynodon nitidus*, and *Polypogon linearis*

Fig. 2. Accumulated number of specimens and accumulated number of species collected in Chile in the 18 decades between 1828 and 2007.

In Antofagasta there were 125 taxa, and a greater collection effort (Table 1); in comparison with the other two regions of "Norte Grande", in Antofagasta reside a greater number of endemic species: *Anatherostipa venusta*, *Festuca morenensis*, *F. tunicata*, *F. werdermannii*, *Jarava matthei*, *J. tortuosa*, *Nassella pungens*, *Poa paposana*, and *Polypogon linearis*.

In the near north, we found two regions: Atacama (AT) and Coquimbo (CO), located between the hyper-arid region of Antofagasta and the more fertile region of Central Chile, between the rivers Copiapó and Aconcagua. In Atacama, only 106 taxa were recognized, of which 58 are native or endemic, while other six species were included in the Catalogue of the vascular flora of Atacama (Squeo et al. 2008). Nevertheless, the collection index shows a relatively small collection effort for grasses in Atacama (Table 1). Endemic species in Atacama are *Festuca werdermannii*, *Jarava tortuosa*, *Nassella duriuscula*, *N. pungens*, and *Poa paposana*.

In Coquimbo there is an increase of the taxonomic biodiversity, coupled with an increased collection effort. The number of taxa reaches 167, which corresponds to the highest for Poaceae in northern Chile. According to the Catalogue of the vascular flora of Coquimbo (Marticorena et al., 2001), the flora of this region (native and naturalized) includes 1727 species of which nearly 9% belong to Poaceae. An analysis of the biodiversity of Coquimbo (Squeo et al., 2001) mentions 104 species of Poaceae, the second most diverse family after Asteraceae in Coquimbo. An increase in the number of endemic grasses also takes place (Table 1). There are 26 endemic grasses belonging to 12 genera. The high degree of endemic species of Poaceae coincides with the high degree of endemism present in this region (53.5% of the vascular flora is endemic to Chile) (Squeo et al., 2001). The subfamily Bambusoideae has its septentrional limit of distribution in the region of Coquimbo. In Fray Jorge, there are 11 species of Poaceae, including *Chusquea cumingii* (Arancio et al., 2004), which represents the northernmost record of subfamily Bambusoideae in Chile.

Central Chile includes the regions of Valparaíso, Metropolitana, O'Higgins, Maule and Bío-Bío, approximately between 32° and 36°S. The high degree of anthropic pressure in central Chile is reflected in the greatest number of introduced species (approx. 10-16% of grasses are adventives). Due to the high percentage of endemic species, the high percentage of introduced species is disquieting as most of them are invasive weeds (Matthei, 1995). As has

Systematic Diversity of the Family Poaceae (Gramineae) in Chile 83

Sobs Chao 2 ICE Jack 2 Bootstrap Michaelis-Menten

Jack 1

AP TA AN AT CO VA ME OH MA BB AR LR LL AY MG

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 **Time**

Fig. 3. Species accumulation curve of observed species (Sobs) in Chile and curves of

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 **Time**

of Chile. See Table 1 for abbreviations of the regional names.

Fig. 4. Species accumulation curves of observed species (Sobs) in the fifteen political regions

estimated number of species calculated using the indices Chao 2, ICE, Jacknife 1, Jacknife 2,

and *N. macrathera, Phalaris amethystina*, and *Poa cumingii*. In the region of Los Ríos 143 taxa were collected, 46 of which are introduced and 13 are endemic to Chile. Endemic species are the following: *Alopecurus lechleri*, *Anthoxanthum altissimum*, *Chusquea macrostachya*, *C. montana*, *C. quila*, *C. uliginosa*, *Danthonia araucana*, *D. chilensis* var. *aureofulva*, *Melica violacea*, *Nassella duriuscula*, *N. juncea* and *N. macrathera*, and *Poa cumingii*. In Los Lagos, 131 taxa were recorded, 38 introduced species, and eight endemic species (*Agrostis insularis*, *Anthoxanthum altissimum*, *Chusquea macrostachya, C. montana, C. quila, C. uliginosa, Poa cumingii*, and

Bootstrap y Michaelis-Menten.

*Polypogon linearis*).

0

50

100

150

**Species**

200

250

300

**Species**

been pointed out, invasive species play a major role in displacing native plants and are the second leading threat to biodiversity following habitat destruction (Holcombe et al., 2010). It has been suggested that approximately 690 species of alien plants have been introduced and became naturalized in Chile, 507 of which reside in the Mediterranean area of central Chile; Poaceae is the most important family, with 151 species (Arroyo et al., 2000).

Easter Island (Isla de Pascua, Rapa Nui) belongs to the Region of Valparaíso in central Chile (27°9'S, 109°27'W) and lies 3700 km off the Chilean coast. The island has a small amount of vegetation. Currently, there are 22 genera and about 200 species of seed plants, most of them introduced (Mann et al., 2003). Introduced grasses (Poaceae) dominate the vegetation while native species number about forty-six. Only eight endemic species remain. All trees are introduced species. The endemic tree *Sophora toromiro* Skottsb. (Fabaceae) disappeared in the 1950's, probably due to animal grazing and anthropogenic impact. A major effort to reintroduce this species on the island has been done by CONAF (Corporación Nacional Forestal) and Jardín Botánico Nacional of Chile. Among grass species *Rytidosperma paschalis* is endemic. Introduced grasses in Easter Island are *Agrostis stolonifera*, *Austrostipa scabra* (sometimes cited as *Stipa horridula* Pilg.), *Avena fatua*, *Briza minor*, *Cenchrus clandestinus*, *C. echinatus*, *Chloris gayana*, *Cynodon dactylon*, *Dichelachne micrantha*, *Digitaria ciliaris*, *D. setigera*, *D. violascens*, *Eleusine indica*, *Eragrostis atrovirens*, *Gastridium phleoides*, *Hordeum murinum*, *Lachnagrostis filiformis*, *Lolium perenne*, *Melinis repens*, *Poa annua*, *Setaria parviflora*, *Sorghum halepense*, *Sporobolus indicus*, *S. africanus* (cultivated for grazing purpose), and *Vulpia myuros*. Native grasses: *Axonopus compressus* (sometimes cited under the name *A. paschalis*) *Bromus catharticus*, *Paspalum dasypleurum*, *P. dilatatum*, *P. forsterianum*, and *P. scrobiculatum* var. *orbiculare* (Giraldo-Cañas, 2008; Mann et al., 2003; Markgraf, 2003; Matthei, 1995; Skottsberg, 1956; Steadman, 1995).

In the archipelago of Juan Fernández (Region of Valparaíso), Poaceae is represented by approximately 35 genera and 61 species. Most of the species belong to the subfamily Pooideae (44 spp., 72%) and Panicoideae (9 spp., 14%). Only two Bambusoideae are found, *Chusquea fernandeziana*, endemic to Masatierra, and *C. culeou* (Baeza et al., 2007), one cultivated species of the subfamily Arundinoideae (*Arundo donax*), two species of Danthonioideae (*Danthonia chilensis* and *D. malacantha*), and two species of Chloridoideae (*Cynodon dactylon* and *Eleusine tristachya*). Five species are endemic: *Agrostis masafuerana* Pilg. (Masafuera), *Chusquea fernandeziana* (Masatierra), *Megalachne berteroana* and *M. masafuerana* (Masatierra and Masafuera), and *Podophorus bromoides* possibly extinct (Baeza et al, 2002; Baeza et al., 2007). *Polypogon imberbis* is considered endemic to Juan Fernández, but occasionally found in continental Chile (Müller, 1985). *Megalachne* and *Podophorus* are endemic genera.

The regions with greater diversity of Poaceae in Central Chile were Bío-Bío, Metropolitan, and Valparaíso, with 263, 198, and 186 taxa, respectively. According to our data, 57 species of grasses from 21 genera of grasses endemic to Chile are found in the area of the Chilean hotspot. On the other hand, O'Higgins is the most weakly collected region in Central Chile. Our data show that only 55% of the estimated grass flora in this region is represented in the Herbarium collections.

Southern Chile includes the regions of Araucanía, Los Ríos and Los Lagos, from approx. 37°S to 43°S. The Region of Araucanía is the best collected. There are 188 known taxa of Poaceae, of which 57 are introduced and 14 are endemic: *Anthoxanthum altissimum*, *A. spicatum*, *Bromidium trisetoides*, *Chusquea quila*, *Danthonia araucana*, *D. chilensis* var. *aureofulva*, *Deschampsia monandra*, *Gymnachne koelerioides*, *Melica violacea*, *Nassella duriuscula*, *N. juncea* 

been pointed out, invasive species play a major role in displacing native plants and are the second leading threat to biodiversity following habitat destruction (Holcombe et al., 2010). It has been suggested that approximately 690 species of alien plants have been introduced and became naturalized in Chile, 507 of which reside in the Mediterranean area of central Chile;

Easter Island (Isla de Pascua, Rapa Nui) belongs to the Region of Valparaíso in central Chile (27°9'S, 109°27'W) and lies 3700 km off the Chilean coast. The island has a small amount of vegetation. Currently, there are 22 genera and about 200 species of seed plants, most of them introduced (Mann et al., 2003). Introduced grasses (Poaceae) dominate the vegetation while native species number about forty-six. Only eight endemic species remain. All trees are introduced species. The endemic tree *Sophora toromiro* Skottsb. (Fabaceae) disappeared in the 1950's, probably due to animal grazing and anthropogenic impact. A major effort to reintroduce this species on the island has been done by CONAF (Corporación Nacional Forestal) and Jardín Botánico Nacional of Chile. Among grass species *Rytidosperma paschalis* is endemic. Introduced grasses in Easter Island are *Agrostis stolonifera*, *Austrostipa scabra* (sometimes cited as *Stipa horridula* Pilg.), *Avena fatua*, *Briza minor*, *Cenchrus clandestinus*, *C. echinatus*, *Chloris gayana*, *Cynodon dactylon*, *Dichelachne micrantha*, *Digitaria ciliaris*, *D. setigera*, *D. violascens*, *Eleusine indica*, *Eragrostis atrovirens*, *Gastridium phleoides*, *Hordeum murinum*, *Lachnagrostis filiformis*, *Lolium perenne*, *Melinis repens*, *Poa annua*, *Setaria parviflora*, *Sorghum halepense*, *Sporobolus indicus*, *S. africanus* (cultivated for grazing purpose), and *Vulpia myuros*. Native grasses: *Axonopus compressus* (sometimes cited under the name *A. paschalis*) *Bromus catharticus*, *Paspalum dasypleurum*, *P. dilatatum*, *P. forsterianum*, and *P. scrobiculatum* var. *orbiculare* (Giraldo-Cañas, 2008; Mann et al., 2003; Markgraf, 2003; Matthei, 1995; Skottsberg,

In the archipelago of Juan Fernández (Region of Valparaíso), Poaceae is represented by approximately 35 genera and 61 species. Most of the species belong to the subfamily Pooideae (44 spp., 72%) and Panicoideae (9 spp., 14%). Only two Bambusoideae are found, *Chusquea fernandeziana*, endemic to Masatierra, and *C. culeou* (Baeza et al., 2007), one cultivated species of the subfamily Arundinoideae (*Arundo donax*), two species of Danthonioideae (*Danthonia chilensis* and *D. malacantha*), and two species of Chloridoideae (*Cynodon dactylon* and *Eleusine tristachya*). Five species are endemic: *Agrostis masafuerana* Pilg. (Masafuera), *Chusquea fernandeziana* (Masatierra), *Megalachne berteroana* and *M. masafuerana* (Masatierra and Masafuera), and *Podophorus bromoides* possibly extinct (Baeza et al, 2002; Baeza et al., 2007). *Polypogon imberbis* is considered endemic to Juan Fernández, but occasionally found in

The regions with greater diversity of Poaceae in Central Chile were Bío-Bío, Metropolitan, and Valparaíso, with 263, 198, and 186 taxa, respectively. According to our data, 57 species of grasses from 21 genera of grasses endemic to Chile are found in the area of the Chilean hotspot. On the other hand, O'Higgins is the most weakly collected region in Central Chile. Our data show that only 55% of the estimated grass flora in this region is represented in the

Southern Chile includes the regions of Araucanía, Los Ríos and Los Lagos, from approx. 37°S to 43°S. The Region of Araucanía is the best collected. There are 188 known taxa of Poaceae, of which 57 are introduced and 14 are endemic: *Anthoxanthum altissimum*, *A. spicatum*, *Bromidium trisetoides*, *Chusquea quila*, *Danthonia araucana*, *D. chilensis* var. *aureofulva*, *Deschampsia monandra*, *Gymnachne koelerioides*, *Melica violacea*, *Nassella duriuscula*, *N. juncea* 

continental Chile (Müller, 1985). *Megalachne* and *Podophorus* are endemic genera.

Poaceae is the most important family, with 151 species (Arroyo et al., 2000).

1956; Steadman, 1995).

Herbarium collections.

Fig. 3. Species accumulation curve of observed species (Sobs) in Chile and curves of estimated number of species calculated using the indices Chao 2, ICE, Jacknife 1, Jacknife 2, Bootstrap y Michaelis-Menten.

and *N. macrathera, Phalaris amethystina*, and *Poa cumingii*. In the region of Los Ríos 143 taxa were collected, 46 of which are introduced and 13 are endemic to Chile. Endemic species are the following: *Alopecurus lechleri*, *Anthoxanthum altissimum*, *Chusquea macrostachya*, *C. montana*, *C. quila*, *C. uliginosa*, *Danthonia araucana*, *D. chilensis* var. *aureofulva*, *Melica violacea*, *Nassella duriuscula*, *N. juncea* and *N. macrathera*, and *Poa cumingii*. In Los Lagos, 131 taxa were recorded, 38 introduced species, and eight endemic species (*Agrostis insularis*, *Anthoxanthum altissimum*, *Chusquea macrostachya, C. montana, C. quila, C. uliginosa, Poa cumingii*, and *Polypogon linearis*).

Fig. 4. Species accumulation curves of observed species (Sobs) in the fifteen political regions of Chile. See Table 1 for abbreviations of the regional names.

Systematic Diversity of the Family Poaceae (Gramineae) in Chile 85

Bambusoideae are represented in Chile only by the genus *Chusquea* (Bambuseae, Chusqueinae). This diverse genus comprises some 134 described species; notwithstanding, some 70 species remain undescribed (Judziewicz et al. 1999). The genus *Chusquea* is exclusively American, growing from Mexico to Chile and Argentina, from approximately 24°N to 47°S and from see level to approximately 4000 m of altitude. Ten species and one variety grow in Chile, seven species are endemic (Tables 2 and 3). In Chile, the species of *Chusquea* are usually associated to forest margins, from approx. 30°S (Coquimbo) to 46°40'S (Aysén), and from the see level to 2300 m in the Andes. The most widely distributed species in Chile is *C. culeou* (coligüe), living from Choapa (31 ° S) to Aysén (45 °S) between the see level to ca. 2000 m of altitude; this species lives also in Argentina. Common to Chile and Argentina are also *C. andina*, *C. montana* f. *montana* (tihuén) and *C. valdiviensis* (quila del sur). Although *C. quila* (quila) is considered endemic to Chile, some botanists considered it a synonym of *C. valdiviensis* (Nicora, 1978; Parodi, 1945). Even though *C. quila* has been collected between Valparaíso (33°S) and Aysén (44°S) it has its main distribution between Valparaiso and Ñuble (approx. 36°S), while *C. valdiviensis* is distributed mainly from the Araucanía Region (38°S) to the south (Chiloé, 43°S). *Chusquea andina* lives in the centralsouthern regions of Bío-Bío and Araucanía, above the tree line in the Andes. *Chusquea montana* f. *montana* grows between Ñuble (36°S) and Chiloé (46°S), as well as *C. valdiviensis*. Endemic to Chile are *C. ciliata*, *C. cumingii*, *C. fernandeziana*, *C. macrostachya* (quila), *C. montana* f. *nigricans* (quila enana), *C. quila* and *C. uliginosa*. *Chusquea ciliata* is endemic to the Region of Valparaíso. *Chusquea fernandeziana* is endemic to the Robinson Crusoe or Juan Fernández archipelago, where is found in Masatierra on outcrops between rocks, ravines or forest, usually isolated and sparse (Baeza et al., 2002). When Munro describes *C. ligulata* from Cundinamarca (Colombia), he includes under this name a sterile specimen collected by Bertero in Juan Fernández that possibly corresponds to *C. fernandeziana* (Parodi, 1945). This is, probably, the reason why *C. ligulata* is included sometimes as a synonym of *C. fernandeziana*. However, *C. ligulata* is closer to or conespecific with *C. sneidernii* Asplund of section Longiprophyllae, not to *C. fernandeziana* (Clark, 1990). *Chusquea cumingii* grows between Limarí (Region of Coquimbo, 30 °S) and Ñuble (36 °S), usually below 1500 m of altitude. *Chusquea macrostachya* has been collected between Santiago and Chiloé (33-43°S) but it is found more frequently in the southern regions of the country into the forest under the canopy or in canopy gaps as well as in roadsides. *Chusquea uliginosa* (quila de los ñadis), is found from Valdivia to Aysén (39-44°S), below 1500 m of altitude, in the central valley. The species of *Chusquea* are known in Chile by the vernacular names "coligües" or "quilas". Indigenous people ("mapuches") used the culms of *C. culeou* (coligüe) to build partitions inside their houses ("rucas"), musical instruments ("trutrucas") or fences, and used quilas (*C. quila*, *C. cumingii*), as forage for livestock. Currently, craftsmen use coligües to build furniture. Although coligües are not widely used in the industry, some properties like specific gravity, fiber length and chemical constitution suggest that this plant could be used as raw material for paper and for particle or fiber board production (Poblete et al., 2009).

In Chile, Ehrhartoideae are absent from the native grass flora, but both the cultivated (rice) and wild rice (red rice, *Oryza sativa*) are found. Approximately 25,000 ha of rice are grown in a small south-central area of the country, located between O'Higgins (34°S) and Bío-Bío

**5.1.1 Bambusoideae** 

**5.1.2 Ehrhartoideae link** 

Austral Chile, also known as Chilean Patagonia, includes the regions of Aysén and Magallanes and extends from about 43°S to the south. While Aysén has been weekly collected, Magallanes is one of the best known from a floristic point of view (Fig. 5). In Aysén 112 grass species have been collected (Table 1), including 77 native species, 19 introduced species and 4 endemic species (*Anthoxanthum altissimum*, *Chusquea montana*, *C. quila*, and *C. uliginosa*). In Magallanes 158 species have been collected (Table 1). Endemic species in this region are *Alopecurus heleochloides*, *Festuca magensiana*, *Hordeum brachyatherum*. Introduced species number 38 and native species number 117.
