Plant Assessment Form

More Stipa miliacea var. miliacea resources

Stipa miliacea var. miliacea

Synonyms: Piptatherum miliaceum; Agrostis miliacea L., Oryzopsis miliacea

Common Names: smilo grass; bamboo grass; milo; ricegrass; rice millet; millet mountain-rice; San Diego grass

Evaluated on: 8/2/04

List committee review date: 27/08/2004

Re-evaluation date:

Evaluator(s)

Jonathan C. Fox/ Research Associate
California Polytechnic State University, San Luis Obispo
591 Rosina Dr. Los Osos, CA 93402
(805)528-7091
anyplacewild@kcbx.net

List committee members

John Randall
Cyntia Roye
Joe DiTomaso
Peter Warner
Alison Stanton
Jake Sigg

General Comments

Origin - Mediterranean
Removed second scientific name, Piptatherum miliaceum, and added it to the synonym line 3/28/17. Ramona Robison

Table 2. Criteria, Section, and Overall Scores

Overall Score? Limited

Alert Status? No Alert

Documentation? 2.5 out of 5

Score

Documentation

1.1

?Impact on abiotic ecosystem processes

U. Unknown

Reviewed Scientific Publication

Impact?
Four-part score UBUC Total Score
C

1.2

?Impact on plant community

B. Moderate

Observational

1.3

?Impact on higher trophic levels

U. Unknown

1.4

?Impact on genetic integrity

C. Minor/Low

Other Published Material

2.1

?Role of anthropogenic and natural disturbance in establishment

B. Moderate

Reviewed Scientific Publication

Invasiveness?
Total Points
14 Total Score B

2.2

?Local rate of spread with no management

A. Increases rapidly

Observational

2.3

?Recent trend in total area infested within state

B. Increasing less rapidly

Other Published Material

2.4

?Innate reproductive potential
(see Worksheet A)

A. High

Other Published Material

2.5

?Potential for human-caused dispersal

B. Moderate

Other Published Material

2.6

? Potential for natural long-distance dispersal

C. Rare

Other Published Material

2.7

?Other regions invaded

C. Already invaded

Other Published Material

3.1

?Ecological amplitude/Range
(see Worksheet C)

A. Widespread

Other Published Material

Distribution?
Total Score B

3.2

?Distribution/Peak frequency
(see Worksheet C)

D. Very low

Observational

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".

Section 1: Impact
Question 1.1 Impact on abiotic ecosystem processes? Consider the impact on the natural range and variation of abiotic ecosystem processes and system-wide parameters in ways that significantly diminish the ability of native species to survive and reproduce. Alterations that determine the types of communities that can exist in a given area are of greatest concern. Examples of abiotic processes include: - fire occurrence, frequency, and intensity; - geomorphological changes such as erosion and sedimentation rates; - hydrological regimes, including soil water table; - nutrient and mineral dynamics, including salinity, alkalinity, and pH; - light availability (e.g. when an aquatic invader covers an entire water body that would otherwise be open). Select the one letter below that best describes this species' most severe impact on an abiotic ecosystem process: A. Severe, possibly irreversible, alteration or disruption of an ecosystem process. B. Moderate alteration of an ecosystem process. C. Minor alteration of an ecosystem process. D. Negligible perceived impact on an ecosystem process. U. Unknown.	U Reviewed Scientific Publication
Identify ecosystem processes impacted: Sources of information:
Question 1.2 Impact on plant community composition, structure, and interactions? Consider the cumulative ecological impact of this species to the plant communities it invades. Give more weight to changes in plant composition, structure, and interactions that involve rare or keystone species or rare community types. Examples of severe impacts include: - formation of stands dominated (>75% cover) by the species; - occlusion (>75% cover) of a native canopy, including a water surface, that eliminates or degrades layers below; - significant reduction or extirpation of populations of one or more native species. Examples of impacts usually less than severe include: - reduction in propagule dispersal, seedling recruitment, or survivorship of native species; - creation of a new structural layer, including substantial thatch or litter, without elimination or replacement of a pre-existing layer; - change in density or depth of a structural layer; - change in horizontal distribution patterns or fragmentation of a native community; - creation of a vector or intermediate host of pests or pathogens that infect native plant species. Select the one letter below that best describes this species' impact on community composition, structure and interactions: A. Severe alteration of plant community composition, structure, or interactions. B. Moderate alteration of plant community composition. C. Minor alteration of community composition. D. Negligible impact known; causes no perceivable change in community composition, structure, or interactions. U. Unknown.	B Observational
Identify type of impact or alteration: Impacts community composition of riparian understory vegetation. Alters structure of grassland areas. Competes with and crowds out riparian understory vegetation. P. miliaceum is larger in stature than most native grasses. Grassland structure is altered by formation of small monospecific stands of P. miliaceum which creates a raised canopy. Sources of information: (1) Knapp, J.J. 2004. Personal observation during 2003 field surveys on Santa Catalina Island, CA. (310)510-1299, knappweed@catalinaisp.com
Question 1.3 Impact on higher trophic levels? Consider the cumulative impact of this species on the animals, fungi, microbes, and other organisms in the communities that it invades. Although a non-native species may provide resources for one or a few native species (e.g. by providing food, nesting sites, etc.), the ranking should be based on the species' net impact on all native species. Give more weight to changes in composition and interactions involving rare or keystone species or rare community types. Examples of severe impacts include: - extirpation or endangerment of an existing native species or population; - elimination or significant reduction in native species' nesting or foraging sites, cover, or other critical resources (i.e., native species habitat), including migratory corridors. Examples of impacts that are usually less than severe include: - minor reduction in nesting or foraging sites, cover, etc. for native animals; - minor reduction in habitat connectivity or migratory corridors; - interference with native pollinators; - injurious components, such as awns or spines that damage the mouth and gut of native wildlife species, or production of anti-digestive or acutely toxic chemical that can poison native wildlife species. Select the one letter below that best describes this species' impact on community composition and interactions: A. Severe alteration of higher trophic populations, communities, or interactions. B. Moderate alteration of higher trophic level populations, communities, or interactions. C. Minor alteration of higher trophic level populations, communities or interactions. D. Negligible impact; causes no perceivable change in higher trophic level populations, communities, or interactions. E. Unknown.	U
Identify type of impact or alteration: Sources of information:
Question 1.4 Impact on genetic integrity? Consider whether the species can hybridize with and influence the proportion of individuals with non-native genes within populations of native species. Mechanisms and possible outcomes include: - production of fertile or sterile hybrids that can outcompete the native species; - production of sterile hybrids that lower the reproductive output of the native species. Select the one letter below that best describes this species' impact on genetic integrity: A. Severe (high proportion of individuals). B. Moderate (medium proportion of individuals). C. Minor (low proportion of individuals). D. No known hybridization. U. Unknown.	C Other Published Material
Members of this genus have been known to hibridize with Achnatherum hymenoides (INDIAN RICEGRASS)(1). A. hymenoides and P. miliaceum have overlapping ranges in Southern Coastal California(2). A. hymenoides is also sold as a horticultural plant(2). Hybridization may occur in other areas of California with horticultural plantings of A. hymenoides and infestations of P. miliaceum. Sources of information: (1) Watson, L. and Dallwitz, M.J. (1992 onwards). Grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatom, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. http://biodiversity.uno.edu/delta/. Version: 18th August 1999. (2) Hickman, J.C. ed.(1996). The Jepson Manual: higher plants of California. University of California Press, Ltd. London England. pg 1226 & 1283.
Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance in establishment? Assess this species' dependence on disturbance: both human and natural: for establishment in wildlands. Examples of anthropogenic disturbances include: - grazing, browsing, and rooting by domestic livestock and feral animals; - altered fire regimes, including fire suppression; - cultivation; - silvicultural practices; - altered hydrology due to dams, diversions, irrigation, etc.; - roads and trails; - construction; - nutrient loading from fertilizers, runoff, etc. Examples of natural disturbance include: - wildfire; - floods; - landslides; - windthrow; - native animal activities such as burrowing, grazing, or browsing. Select the first letter in the sequence below that describes the ability of this species to invade wildlands: A. Severe invasive potential: this species can establish independent of any known natural or anthropogenic disturbance. B. Moderate invasive potential: this species may occasionally establish in undisturbed areas but can readily establish in areas with natural disturbances. C. Low invasive potential: this species requires anthropogenic disturbance to establish. D. No perceptible invasive potential: this species does not establish in wildlands (though it may persist from former cultivation). U. Unknown.	A Observational
Describe role of disturbance: Typically found in areas with anthropogenic disturbance as well as natural disturbance. In semi-arid areas P. miliaceum may invade undisturbed areas. Literature for California describe habitats invaded as roadsides, fields and waste places(1). These are typically anthropogenic disturbances. P. miliaceum has also been described in riparian areas(1), on animal trails and near ground squirrel mounds(2). In East and South East Spain(native range), literature describes P. miliaceum in semi-arid grasslands(3). A study on the effects of arbuscular mycorrhizal on the development of plants colonizing a semi-arid area in Spain found P. miliaceum to have 100% survivability with or without the mycorrhizal treatment. Mycorrhizal innoculation showed no improvement in growth but significantly increased the number of seedlings germinated in the soil surrounding the mychorrhizal plant(3). This may facilitate invasion by P. miliaceum into undisturbed areas where these mycorrhizal relationships exist. Sources of information: (1) DiTomaso J., Healy E. Weeds of California and Other Western States. As yet unpublished. pg. 570 (2) Knapp, J.J. 2004. Personal observations during 2003 field surveys on Santa Catalina Island, CA. (310) 510-1299, knappweed@catalinaisp.com. (3) Roldan-Fajardo, B.E. 1994. Effect of indigenous arbuscular mycorrhizal endophytes on the development of six wild plants colonizing a semi-arid area in south-east Spain. New Phytologist. 127(1): 115-121.
Question 2.2 Local rate of spread with no management? Assess this species' rate of spread in existing localized infestations where the proportion of available habitat invaded is still small when no management measures are implemented. Select the one letter below that best describes the rate of spread: A. Increases rapidly (doubling in <10 years) B. Increases, but less rapidly C. Stable D. Declining U. Unknown	A Observational
Describe rate of spread: Extensive drainage segments exist on Santa Catalina Island that are still open to invasion, allowing P. miliaceum to increase within the Island (1). Neither floras for Santa Catalina Island list P. miliaceum, but by 2003, 2,854 populations were recorded (2). Sources of information: (1) Knapp, J.J. 2004. Personal observation during 203 field surveys on Santa Catalina Island, CA. (310)510-1299, knappweed@catalinaisp.com (2) Knapp, J.J. 2004. Prioritized invasive plant management plan for the Santa Catalina Island Conservancy. Unpublished.
Question 2.3 Recent trend in total area infested within state? Assess the overall trend in the total area infested by this species statewide. Include current management efforts in this assessment and note them. Select the one letter below that best describes the current trend: A. Increasing rapidly (doubling in total range statewide in <10 years) B. Increasing, but less rapidly C. Stable D. Declining U. Unknown	B Other Published Material
Describe trend: Listed by the Santa Barbara Botanic Garden as a species that should be eradicated when encountered on private property near wildlands (1). On Santa Catalina Island, P. miliaceum is one of the most wide spread species totalling 356 acres (2), but there has not been a concerted effort to reduce its abundance (3). Using information from Catalina Island because not much published information on this plant. Sources of information: (1)Santa Barbara Botanic Garden. No date. Worst invasive plants in Santa Barbara County: exotic species to eradicate if found on your property. http://www.santabarbarabotanicgarden.org/sections/visitor_info/visitor_level_3/visitor. (2)Knapp, J.J. 2004. Prioritized invasive plant management plan for the Santa Catalina Island Conservancy. Unpublished. 1) Knapp, J.J. 2004. Personal observation during 203 field surveys on Santa Catalina Island, CA. (310)510-1299, knappweed@catalinaisp.com
Question 2.4 Innate reproductive potential? Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.	A Other Published Material
Describe key reproductive characteristics: Perennial (2) that reproduces by seed (1). Flowers April to September (2). P. miliaceum is both self and cross pollinated (3). Resporouts from underground rhizomes when cut (4). Sources of information: (1) DiTomaso J., Healy E. Weeds of California and Other Western States. As yet unpublished. pg. 570 (2) Wilken, D. and Hannah, L. 1998. Piptatherum miliaceum: Channel Islands National Park Service literature review. Unpublished. (3) Watson, L. and Dallwitz, M.J. (1992 onwards). Grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatom, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. http://biodiversity.uno.edu/delta/. Version: 18th August 1999. (4) Park, J., Allanson, A. and Tucker, P. No date. Rice millet (not a native grass) - Piptatherum miliaceum. Bushland weeds of South Australia. http://www.treesforlife.org.au/rogues/weeds/ricemillet.html. (5) Observational List Committee, 8/2004.
Question 2.5 Potential for human-caused dispersal? Assess whether this species is currently spread: or has high potential to be spread: by direct or indirect human activity. Such activity may enable the species to overcome natural barriers to dispersal that would not be crossed otherwise, or it may simply increase the natural dispersal of the species. Possible mechanisms for dispersal include: - commercial sales for use in agriculture, ornamental horticulture, or aquariums; - use as forage, erosion control, or revegetation; - presence as a contaminant (seeds or propagules) in bulk seed, hay, feed, soil, packing materials, etc.; - spread along transportation corridors such as highways, railroads, trails, or canals; - transport on boats or boat trailers. Select the one letter below that best describes human-caused dispersal and spread: A. High: there are numerous opportunities for dispersal to new areas. B. Moderate: human dispersal occurs, but not at a high level. C. Low: human dispersal is infrequent or inefficient. D. Does not occur. U. Unknown.	B Other Published Material
Identify dispersal mechanisms: P. miliaceum has been used in the revegetation of frequently burned chaparral (1). It is sometimes cultivated for livestock forage (2). Sources of information: (1) Wilken, D. and Hannah, L. 1998. Piptatherum miliaceum: Channel Islands National Park Service literature review. Unpublished. (2) DiTomaso J., Healy E. Weeds of California and Other Western States. As yet unpublished. pg. 570
Question 2.6 Potential for natural long-distance dispersal? We have chosen 1 km as the threshold of "long-distance." Assess whether this species is frequently spread, or has high potential to be spread, by animals or abiotic mechanisms that can move seed, roots, stems, or other propagules this far. The following are examples of such natural long-distance dispersal mechanisms: - the species' fruit or seed is commonly consumed by birds or other animals that travel long distances; - the species' fruits or seeds are sticky or burred and cling to feathers or hair of animals; - the species has buoyant fruits, seeds, or other propagules that are dispersed by flowing water; - the species has light propagules that promote long-distance wind dispersal; - The species, or parts of it, can detach and disperse seeds as they are blown long distances (e.g., tumbleweed). Select the one letter below that best describes natural long-distance dispersal and spread: A. Frequent long-distance dispersal by animals or abiotic mechanisms. B. Occasional long-distance dispersal by animals or abiotic mechanisms. C. Rare dispersal more than 1 km by animals or abiotic mechanisms. D. No dispersal of more than 1 km by animals or abiotic mechanisms. U. Unknown.	C Other Published Material
Identify dispersal mechanisms: P. miliaceum reproduces by seed. Seeds of plant disperse to greater distances with water, soil movement, human activities, and possibly animals. Sources of information: (1) DiTomaso, JM, E Healy. Weeds of California and Other Western States. Not yet published. (2) Observational, List Committee, 8/2004.
Question 2.7 Other regions invaded? Assess whether this species has invaded ecological types in other states or countries outside its native range that are analogous to ecological types not yet invaded in your state (see Worksheets B, C, and D for California, Arizona, and Nevada, respectively, in Part IV for lists of ecological types). This information is useful in predicting the likelihood of further spread within your state. Select the one letter below that best describes the species' invasiveness in other states or countries, outside its native range. A. This species has invaded 3 or more ecological types elsewhere that exist in your state and are as yet not invaded by this species (e.g. it has invaded Mediterranean grasslands, savanna, and maquis in southern Europe, which are analogous to California grasslands, savanna, and chaparral, respectively). B. Invades 1 or 2 ecological types that exist but are not yet invaded in your state. C. Invades elsewhere but only in ecological types that it has already invaded in the state. D. Not known as an escape anywhere else. U. Unknown.	C Other Published Material
Identify other regions: P. miliaceum has been reported as waif in Great Britain and has become naturalized in California, western Nevada, and Australia (1). It can also be found in Arizona, Idaho, Utah, and a few northeastern states (2). Sources of information: (1) Wilken, D. and Hannah, L. 1998. Piptatherum miliaceum: Channel Islands National Park Service literature review. Unpublished. (2) DiTomaso J., Healy E. Weeds of California and Other Western States. As yet unpublished. pg. 570
Section 3: Distribution
Question 3.1 Ecological amplitude/Range? Refer to Worksheet C and select the one letter below that indicates the number of different ecological types that this species invades. A. Widespread: the species invades at least three major types or at least six minor types. B. Moderate: the species invades two major types or five minor types. C. Limited: the species invades only one major type and two to four minor types. D. Narrow: the species invades only one minor type. U. Unknown.	A Other Published Material
Introduced to California around the turn of the 19th entury from southern Europe(Los Angeles in 1896, Santa Barbara and Monrovia in 1916), and was reported mostly in urban waste areas in urban southern California by 1940. It has been reported from all four northern California Channel Islands and is now known from most southern California counties (1). According to the Jepson Manual (4) P. miliaceum can be found: North Coast, Central Valley, Central Coast, Central-western region, South Coast, to 300 m. P. miliaceum occurs in dry or moist sites in disturbed areas, roadsides and ditches (1). Some ecotypes may be found on acid soils (2) In California it appears to be increasing in riparian areas, ditches along roadsides, and canyons, especially in the southern region (3). On Santa Catalina Island 2,854 populations of smilo were GPS'd. These populations invadedriparian, grassland, coastalscrub/grassland, coastal scrub, chaparral, bare, dune, non-native and oak woodland habitats (5). Aluminum (Al) toxicity has been identified as one of the most important growth-limiting factors in acid soils. Some ecotypes of P. miliaceum have been found to be Al-tolerant (2) Sources of information: (1) Wilken, D. and Hannah, L. 1998. Piptatherum miliaceum: Channel Islands National Park Service literature review. Unpublished (2) Zavas, T.; Symeonidis, L.; Karataglis, S. 1996. Responses to aluminum toxicity effects of two populations of Piptatherum miliaceum (L.) Cosson. Journal of Agronomy & Crop Science. 177(1): 25-32 (3) DiTomaso J., Healy E. Weeds of California and Other Western States. As yet unpublished. pg. 570 (4) Hickman, J.C. ed.(1993). The Jepson Manual: higher plants of California. University of California Press, Ltd. London England. pg 1226 & 1283. (5) Knapp, J.J. 2004. Prioritized invasive plant management plan for the Santa Catalina Island Conservancy. Unpublished.
Question 3.2 Distribution/Peak frequency? To assess distribution, record the letter that corresponds to the highest percent infested score entered in Worksheet C for any ecological type.	D Observational
Describe distribution: Occurs in less than 5% of any ecotype in CA. Sources of information: Observational, List Committee, 8/2004.

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less	Yes
Dense infestations produce >1,000 viable seed per square meter	Yes
Populations of this species produce seeds every year.	Yes
Seed production sustained over 3 or more months within a population annually	No
Seeds remain viable in soil for three or more years	Unknown
Viable seed produced with both self-pollination and cross-pollination	Yes
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes	No
Fragments easily and fragments can become established elsewhere	No
Resprouts readily when cut, grazed, or burned	Yes
Total points:	6
Total unknowns:	1
Total score:	A? Scoring Criteria for Worksheet A A. High reproductive potential (6 or more points). B. Moderate reproductive potential (4-5 points). C. Low reproductive potential (3 points or less and less than 3 Unknowns). U. Unknown (3 or fewer points and 3 or more Unknowns).

Related traits:

Worksheet B - Arizona Ecological Types is not included here

Worksheet C - California Ecological Types

(sensu Holland 1986)

Major Ecological Types	Minor Ecological Types	Code? A means >50% of type occurrences are invaded; B means 20% to 50%; C means 5% to 20%; D means present but <5%; U means unknown (unable to estimate percentage of occurrences invaded)
Marine Systems	marine systems
Freshwater and Estuarine	lakes, ponds, reservoirs
Aquatic Systems	rivers, streams, canals
Aquatic Systems	estuaries
Dunes	coastal	D, < 5%
	desert
	interior
Scrub and Chaparral	coastal bluff scrub
	coastal scrub	D, < 5%
	Sonoran desert scrub
	Mojavean desert scrub (incl. Joshua tree woodland)
	Great Basin scrub
	chenopod scrub
	montane dwarf scrub
	Upper Sonoran subshrub scrub
	chaparral	D, < 5%
Grasslands, Vernal Pools, Meadows, and other Herb Communities	coastal prairie	D, < 5%
	valley and foothill grassland	D, < 5%
	Great Basin grassland
	vernal pool
	meadow and seep
	alkali playa
	pebble plain
Bog and Marsh	bog and fen
Bog and Marsh	marsh and swamp
Riparian and Bottomland habitat	riparian forest
	riparian woodland
	riparian scrub (incl.desert washes)	D, < 5%
Woodland	cismontane woodland
	piñon and juniper woodland
	Sonoran thorn woodland
Forest	broadleaved upland forest
	North Coast coniferous forest
	closed cone coniferous forest
	lower montane coniferous forest
	upper montane coniferous forest
	subalpine coniferous forest
Alpine Habitats	alpine boulder and rock field
Alpine Habitats	alpine dwarf scrub
	Amplitude (breadth):	A
	Distribution (highest score):	D

Infested Jepson Regions

Click here for a map of Jepson regions

CA Floristic Province
Central West
Great Valley
Northwest
Sierra Nevada
Desert Province
Mojave Desert

California Invasive Plant Council

Protecting California’s environment and economy from invasive plants

Plant Assessment Form

More Stipa miliacea var. miliacea resources

Stipa miliacea var. miliacea

Evaluator(s)

List committee members

General Comments

Table 2. Criteria, Section, and Overall Scores

Table 3. Documentation

Worksheet A - Innate reproductive potential

Related traits:

Worksheet C - California Ecological Types

Infested Jepson Regions