Common reed, common reedgrass, giant reed, phrag, Arundo altissima Benth., Arundo australis Cav., Arundo graeca Link, Arundo isiaca Delile, Arundo maxima Forssk., Arundo occidentalis Sieber ex Schult., Arundo palustris Salisb., Arundo phragmites L., Arundo vulgaris Lam., Cynodon phragmites (L.) Raspail, Oxyanthe phragmites (L.) Nieuwl., Phragmites altissimus (Benth.) Mabille ex Debeaux, Phragmites australis var. berlandieri (E. Fourn.) C.F. Reed, Phragmites australis ssp. maximus (Forssk.) Soó, Phragmites berlandieri E. Fourn., Phragmites capensis Nees, Phragmites caudatus Nees ex Meyen, Phragmites chilensis Steud., 

Leaves and Stems:

Culms (stems) erect; hollow; reed-like; simple; 150–600 cm long; 5-15 mm thick; hollow internodes (Clayton et al. 2006, Klein 2011). Culms are tan in color; ridged or ribbed; have a rougher texture than the native common reed (Swearingen and Saltonstall 2010).
Leaves are linear to lanceolate-linear; flat; drooping; leaf-blades deciduous at the ligule; 20–60 cm long; 8–32 mm wide with pointed tips (Clayton et al. 2006, Klein 2011). Leaf blade surface smooth; cauline (Clayton et al. 2006). Leaves are blue green and usually darker than the native lineage (Swearingen and Saltonstall 2010). Each leaf consists of a blade and a loose sheath separated ciliate ligules that form minute membranous rims fringed with hairs; 0.2-0.6 mm long (Clayton et al. 2006, Klein 2011). Leaf sheaths adhere tightly to culm throughout the growing season; persistent (Swearingen and Saltonstall 2010). Leaf-blade apex attenuates; filiform (Clayton et al. 2006).

Flower-head and Flowers:

Inflorescence a panicle; bearing juvenile spikelets at emergence (Clayton et al. 2006). Panicles are oblong, purplish when young, straw colored at maturity; 15-50 cm long; 6-20 cm wide (Clayton et al. 2006, Klein 2011). Primary panicle branches divided; bearing spikelets almost to the base Clayton et al. 2006). Spikelets solitary; pedicelled (Clayton et al. 2006). Pedicels are filiform (Clayton et al. 2006). Spikelets comprising 3–11 florets; with diminished florets at the apex (Clayton et al 2006, Klein 2011). Spikelets cuneate; laterally compressed; 10–18 mm long; stalked with 6-10 mm long hairs on the stalks; breaking up at maturity (Clayton et al. 2006). Floret callus elongated; 1–1.25 mm long; bearded; obtuse. Glumes are paired; persistent; shorter than spikelets; gaping (Clayton et al. 2006). Lower glume lanceolate; 3–7 mm long; 0.5–0.6 length of upper glume; membranous; without keels; 3–5 veined. Lower glume apex acute. Upper glume lanceolate; 5–10 mm long; without keels; 3–5 veined (Clayton et al. 2006, Klein 2011). Upper glume apex acute (Clayton et al. 2006). Basal florets are sterile florets are male with palea; persist on panicle (Clayton et al. 2006). Lemma are glabrous; lanceolate; 8–15 mm long; membranous; acuminate; with somewhat in-rolled margins. Lower lemmas are unawned and upper lemmas are awned; Lemma apex acuminate (Clayton et al, 2006, Klein 2011). Palea present; with scaberulous keels (Clayton et al. 2006). Flowers typically occur in August and September and form bushy panicles that are usually purple or golden in color with 2 lodicules, 3 anthers, and a glabrous ovary (Clayton et al. 2006, Klein 2011).

Fruit is a caryopsis with an adherent pericarp (Clayton et al. 2006). Seeds     are 2 to 3 mm long (Klein 2011). As seeds mature, the panicles begin to look “fluffy” due to the hairs in the spikelet on the rachilla, and they take on a grey sheen (Saltonstall 2005).

Other Features:

Below ground, Phragmites australis forms a dense network of roots and rhizomes which can go down up to two meters in depth to reach deep ground water (MA DCR 2002). The plant spreads horizontally by sending out underground rhizomes and over ground runners which can grow 10 or more feet in a single growing season if conditions are optimal (Swearingen and Saltonstall 2010).

Distinguishing Between Native and Non-native Phragmites australis:

Many morphological characteristics can be used to distinguish native Phragmites australis subsp. americanus from the introduced lineage Phragmites australis subsp. australis. However, there are many overlaps in characteristics making it necessary to look at multiple factors when making a determination based on morphology. The following characteristics should NOT be used to distinguish populations in southern areas (California to the Gulf of Mexico) where the Gulf coast type may be present as it is very similar in appearance to the introduced lineage (Swearingen and Saltonstall 2010).

Growth Forms:

Introduced Phragmites australis subsp. australis typically forms denser stands than the native Phragmites australis subsp. americanus, the introduced subspecies stands are also more likely to include dead stems from the previous year’s growth (MNFI 2016, Swearingen and Saltonstall 2010). Introduced Phragmites is more likely to form monocultures, outcompeting and excluding other plant species. The native Phragmites, is much less robust, typically occurring in low density stands, and is frequently found with other native plants but it can occasionally occur in very dense stands more typical of the introduced form when enriched with nutrients (MNFI 2016, Swearingen and Saltonstall 2010).

Leaves:

Leaves of the invasive subspecies are a bluish gray-green, while those of the native lineage are typically a lighter yellow-green (MNFI 2016, Swearingen and Saltonstall 2010). This is easiest to see when they grow side-by-side (MNFI 2016).

Leaf Sheaths:

The leaf sheaths of the introduced Phragmites adhere more tightly to the culm and persist as long as it remains standing, whereas those of the native lineage adhere less tightly and peel back eventually dropping off the culm once the leaf dies particularly at the lower nodes exposing the stem below (MNFI 2016, Swearingen and Saltonstall 2010).

Culms and Rhizomes:

Culms of the introduced lineage are rigid and have a rougher texture than the native, which is usually smooth and shiny (MNFI 2016). Culms of the native lineage are more likely to be red, typically around the nodes and where the leaf sheaths have been lost. Whereas the culms of the non-native lineage are usually a dull tan color (MNFI 2016). However, non-native Phragmites has stolons that can grow up to 50 feet or more in a season and may be red, also a little red may occasionally be seen on the culms of the introduced lineage but it is usually limited to lower nodes, which may lead to confusion (MNFI 2016, Swearingen and Saltonstall 2010). Little black spots are sometimes found on the culms of the native lineage, which are caused by a native fungus that has not yet adapted to the introduced form (Swearingen and Saltonstall 2010). The culms of the introduced form may have a sooty like mildew but it does not have the distinctive black fungal spots (Swearingen and Saltonstall 2010). Rhizomes of the native subspecies rarely exceed 15 mm in diameter and are a darker yellow than the introduced lineage (Swearingen and Saltonstall 2010).

Ligules:

The ligule of the introduced lineage is typically less than 1 mm (0.4-0.9 mm) in length. Ligules of the native are more than 1 mm (1-1.7 mm) (Swearingen and Saltonstall 2010). The native Phragmites is less sturdy and therefore its ligule is more likely to shred and fray by midsummer (MNFI 2016).

Glumes:

For the introduced lineage, the upper glume ranges in size from 4.5-7.5 mm, with most being <6 mm and the lower glume ranges in size from 2.5-5.0 mm, most being <4 mm; the native subspecies has an upper glume ranges in size from 5.5-11.5 mm, with most being >6 mm and lower glume is ranges in size from 3.5-6.5 mm, with most being >4 mm (Swearingen and Saltonstall 2010).

Habitats:

Introduced Phragmites is typically found in ditches, disturbed sites, and can tolerate saline habitats. In the Great Lakes basin, it is frequently found on shorelines (MNFI 2016). The native lineage is usually found in fens, sedge meadow, river banks and shores, and the Great Lake shores (MNFI 2016).

Growing Seasons:

Introduced Phragmites begins growing earlier in the season and continues later in the fall than does the native lineage (MNFI 2016).

Phragmites australis subsp. australis is a hardy species that can survive and proliferate in a wide range of environmental conditions, but prefers the wetland-upland interface (Avers et al. 2014). It grows on most soil textures from fine clay to sandy loams and is somewhat tolerant of saline or alkaline conditions (ISSG 2011) and so it is often found at the upper edges of estuaries and on other wetlands (such as grazing marshes) that are occasionally inundated by the sea. It is most often found on disturbed sites with altered hydrology, sedimentation, and nutrient enrichment. The United States Department of Agriculture, Natural Resources Conservation Service (USDA, NRCS) has designated Phragmites australis to be a 'FACW', which is roughly equivalent to a 75% chance of this plant occurring in wetlands (USDA, NRCS 2016). Phragmites can tolerate anoxic conditions, and high salinity in soils, and a wide range of pH from 3.9-8.6 (Fofonoff et al. 2015). Phragmites can also tolerate a wide range of temperatures, but shoots are killed off by severe frost events (Haslam 1972). Below ground, introduced Phragmites forms a dense network of roots and rhizomes that can extend downward over a meter (Swearingen and Saltonstall 2010). Along rivers and coastal shorelines, fragments of rhizomes transported from distant infested sites can settle in new spots and become rooted (Swearingen and Saltonstall 2010). Rhizome fragments may also be moved by heavy machinery (Swearingen and Saltonstall 2010).

Age and Growth:

Introduced Phragmites has an average lifetime of 4.5 years, but may live up to 6 years, when longevity is defined as the lifetime of an individual rhizome, but due to its clonal growth abilities, stands have been known to survive for 1000’s of years (Haslam 1972). Vegetative spread by below-ground rhizomes can result in dense stands that have more than 200 shoots/m2 (Haslam 1972).

Reproduction:

Introduced Phragmites australis reproduces primarily clonally through the production and fragmentation of underground rhizomes, but is capable of sexual reproduction through seeds (Fofonoff et al. 2015). Phragmites is wind-pollinated; cross pollination with other plants is probably most common, but self-pollination or agamospermy may occur (Gucker 2008). Flowering starts in late July (Fofonoff et al. 2016). Seeds are primarily dispersed by wind in the fall and winter months (Fofonoff et al. 2015, Haslem 1972). However, they can also be transported on birds, or by water, via waterways or by flooding (Haslam 1972). Seed set is highly variable, with germination rates that are typically low (Haslam 1972), though mature plants may produce as many as 2,000 seeds annually (Avers et al. 2014). Some sources have even reported as many as 1000 seeds per every inflorescence (Haslam 1972). Local propagation is largely to be considered achieved through vegetative reproduction with seeds responsible for new colonization events (Mark et al. 1994). Plants growing in harsh environments may not be able to flower, so the only mode of reproduction is vegetative (Haslam 1972). Germination takes place on exposed moist soils in spring, at temperatures above 10 C (March-April) (Fofonoff et al. 2015). Water depths greater than 5 cm (2 in) generally prevent germination (Marks et al. 1994). After germination a rhizome takes 2-4 years to flower for the first time (Haslam 1971).

Along rivers and coastal shorelines, fragments of rhizomes transported from distant infested sites can settle in new spots and become rooted (Swearingen and Saltonstall, 2010). Rhizome fragments may also be moved by heavy machinery (Swearingen and Saltonstall, 2010).

Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental	Socioeconomic	Beneficial

The leaves and stems of Phragmites have poor nutritional value and few organisms feed on it in North America, so replacement of native vegetation by the less nutritious Phragmites could have negative consequences for herbivores (Great Lakes Phragmites Collaborative 2023). Larval and juvenile fish seem to be the most negatively affected by Phragmites (Great Lakes Phragmites Collaborative 2023). The species produces abundant litter which can reduce the mobility of juvenile fish.

Phragmites displaces native plant species including sedges, rushes, and cattails; and reduces wildlife habitat diversity, resulting in loss of food and shelter for native wildlife (Avers et al. 2010). In Ontario, Canada, Blanding Turtles (Emydoidea blandingii) avoided nesting in Phragmites  patches thus reducing the amount of suitable nesting habitat available in an invaded marsh areas (Markle and Chow-Fraser, 2018). Its success may also be attributed to allelopathy; Phragmites releases gallic acid, which is degraded by ultraviolet light to produce mesoxalic acid, exposing susceptible plants and seedlings with two harmful toxins (Rudrappa 2009). Furthermore, Phragmites alters wetland hydrology through increased evaporation and trapping of sediments, causing marsh soils to dry out (Avers et al. 2010, Swearingen and Saltonstall 2010). Phragmites also impacts nutrient levels; when meadow marsh were replaced with Phragmites in Long Point peninsula, Ontario, Canada, the stocks of Ca, P, K, N, Mg, and C all increased significantly with a mean increase ranging from 103-188% (Yickin and Rooney, 2019).

Phragmites australis has a moderate socio-economic impact in the Great Lakes.

Tall, dense stands of the introduced Phragmites impede shore access, as penetration of a stand of introduced Phragmites can not only be difficult but can also result in abrasions from the sharp-edged vegetation (Avers et al., 2010, USFWS, 2007). Recreational value for birdwatchers, walkers, naturalists, boaters, and hunters is further diminished through reduction of native fish and wildlife populations (USFWS 2007). Such use impairment and restricted shoreline view also reduce property values (Avers et al. 2010).

In addition to economic impacts, the introduced Phragmites poses a risk to human life and property. The Michigan Department of Transportation (MDOT) considers Phragmites to be a safety hazard, as its height and dense growth may block signs and view of access roads, drives, curves, etc. (B. Batt, MDOT, pers. comm.). During its dormant season, when dry biomass is high, the introduced common reed also creates a potentially serious fire hazard to structures (Avers et al., 2010, Swearingen and Saltonstall 2010).

Phragmites australis has a high beneficial effect in the Great Lakes.

As a wetland plant, Phragmites improves water quality by filtration and nutrient removal (Ailstock, 2004). Phragmites provides food and habitat for some organisms and serves to stabilize soils against erosion. Bobolink and sparrows eat its seeds, while numerous insects eat the vegetation. Moreover, many insects, birds (including yellowthroat, marsh wren, salt marsh sparrow, least bittern, red-winged blackbird, and some wading birds), and muskrats use Phragmites as shelter or nest material (Kiviat, 2010).

Other synonyms: Phragmites communis Trin., Phragmites communis var. berlandieri (E. Fourn.) Fernald, Phragmites communis ssp. berlandieri (E. Fourn.) Á. Löve & D. Löve, Phragmites communis var. flavescens Custer, Phragmites communis var. genuinus Stuck., Phragmites communis var. hispanicus (Nees) K. Richt., Phragmites communis var. isiacus (Delile) Engl., Phragmites communis var. mauritianus (Kunth) Baker, Phragmites communis ssp. maximus (Forssk.) Clayton, Phragmites communis var. variegatus Hitchc. ex L.H. Bailey, Phragmites dioicus Hack. ex Conert, Phragmites dioicus Hack. ex Hicken, Phragmites fissifolius Steud., Phragmites hispanicus Nees, Phragmites isiacus (Delile) Kunth, Phragmites martinicensis Trin. ex Steud., Phragmites mauritianus Kunth, Phragmites maximus (Forssk.) Chiov., Phragmites maximus var. berlandieri (E. Fourn.) Moldenke, Phragmites maximus var. variegatus (Hitchc. ex L.H. Bailey) Moldenke, Phragmites occidentalis Trin. ex Steud., Phragmites phragmites (L.) Speg., Phragmites phragmites (L.) H. Karst., Phragmites vulgaris (Lam.) Crép., Phragmites vulgaris Britton, Sterns & Poggenb., Phragmites vulgaris var. mauritianus (Kunth) T. Durand & Schinz, Phragmites vulgaris ssp. maximus (Forssk.) Chiov., Reimaria diffusa Spreng., Trichoon phragmites (L.) Rendle