Pacific Island Ecosystems at Risk (PIER)
Dasylirion acrotrichum
RISK ASSESSMENT RESULTS: Low risk, score: 0
|
Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i. Information on Risk Assessments Original risk assessment |
| Dasylirion acrotrichum [green desert spoon] (Synonym: Yucca acrotricha, Dasylirion acrotriche, Dasylirion gracile, Bonapartea gracile, Roulinia gracile, Yucca gracile) Previously Agavaceae - now Nolinaceae. | Answer | Score | |
| 1.01 | Is the species highly domesticated? | n | 0 |
| 1.02 | Has the species become naturalized where grown? | n | |
| 1.03 | Does the species have weedy races? | n | |
| 2.01 | Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical” | 2 | |
| 2.02 | Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2 | 2 | |
| 2.03 | Broad climate suitability (environmental versatility) | y | 1 |
| 2.04 | Native or naturalized in regions with tropical or subtropical climates | y | 1 |
| 2.05 | Does the species have a history of repeated introductions outside its natural range? y=-2 | y | |
| 3.01 | Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05 | n | -2 |
| 3.02 | Garden/amenity/disturbance weed y = 1*multiplier (see Append 2) | n | 0 |
| 3.03 | Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2) | n | 0 |
| 3.04 | Environmental weed y = 2*multiplier (see Append 2) | n | 0 |
| 3.05 | Congeneric weed y = 1*multiplier (see Append 2) | n | 0 |
| 4.01 | Produces spines, thorns or burrs | y | 1 |
| 4.02 | Allelopathic | n | 0 |
| 4.03 | Parasitic | n | 0 |
| 4.04 | Unpalatable to grazing animals | ||
| 4.05 | Toxic to animals | n | 0 |
| 4.06 | Host for recognized pests and pathogens | n | 0 |
| 4.07 | Causes allergies or is otherwise toxic to humans | n | 0 |
| 4.08 | Creates a fire hazard in natural ecosystems | y | 1 |
| 4.09 | Is a shade tolerant plant at some stage of its life cycle | n | 0 |
| 4.1 | Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island) | n | 0 |
| 4.11 | Climbing or smothering growth habit | n | 0 |
| 4.12 | Forms dense thickets | n | 0 |
| 5.01 | Aquatic | n | 0 |
| 5.02 | Grass | n | 0 |
| 5.03 | Nitrogen fixing woody plant | n | 0 |
| 5.04 | Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers) | n | 0 |
| 6.01 | Evidence of substantial reproductive failure in native habitat | n | 0 |
| 6.02 | Produces viable seed. | y | 1 |
| 6.03 | Hybridizes naturally | ||
| 6.04 | Self-compatible or apomictic | n | -1 |
| 6.05 | Requires specialist pollinators | ||
| 6.06 | Reproduction by vegetative fragmentation | n | -1 |
| 6.07 | Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1 | 4 | -1 |
| 7.01 | Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas) | y | 1 |
| 7.02 | Propagules dispersed intentionally by people | y | 1 |
| 7.03 | Propagules likely to disperse as a produce contaminant | n | -1 |
| 7.04 | Propagules adapted to wind dispersal | y | 1 |
| 7.05 | Propagules water dispersed | n | -1 |
| 7.06 | Propagules bird dispersed | n | -1 |
| 7.07 | Propagules dispersed by other animals (externally) | n | -1 |
| 7.08 | Propagules survive passage through the gut | n | -1 |
| 8.01 | Prolific seed production (>1000/m2) | y | 1 |
| 8.02 | Evidence that a persistent propagule bank is formed (>1 yr) | ||
| 8.03 | Well controlled by herbicides | n | 1 |
| 8.04 | Tolerates, or benefits from, mutilation, cultivation, or fire | ||
| 8.05 | Effective natural enemies present locally (e.g. introduced biocontrol agents) | ||
| Total score: | 0 |
Supporting data:
| Notes | Reference | |
| 1.01 | No evidence | |
| 1.02 | No evidence | |
| 1.03 | No evidence | |
| 2.01 | Origin: East-central Mexico (Durango, Tamaulipas, Jalisco) | http://www.desert-tropicals.com/Plants/Agavaceae/Dasylirion_acrotriche.html |
| 2.02 | ||
| 2.03 | (1)USDA: 9-11 (2)Several Missouri Botanical Garden herbarium specimens obtained from elevation above 2000 m. mostly from Mexico. | (1)http://www.desert-tropicals.com/Plants/Agavaceae/Dasylirion_acrotriche.html (2)http://mobot.mobot.org/cgi-bin/search_vast |
| 2.04 | Origin: East-central Mexico (Durango, Tamaulipas, Jalisco) | http://www.desert-tropicals.com/Plants/Agavaceae/Dasylirion_acrotriche.html |
| 2.05 | (1)Introduced to the United States. (a)Seeds available for sale online from the following website http://rareseedsource.com/succulents.php - this physical address to obtain seeds from this site is: FutureSystems 1700 Bittersweet Hill Vista, CA 92084. (b) Also available online from http://www.getnet.net/~richarde/cactusstore/CactusCatalog.htm - their plant nursery is located in Phoenix, Nevada.(2)Available for sale from the Trevena Cross Nursery in Cornwall - England. (3)Introduced to England - Sussex | (2)http://www.trevenacross.co.uk/shop/page7b.htm (3)http://www.rhs.org.uk/Learning/publications/pubs/garden0505/oasis.asp |
| 3.01 | No evidence | |
| 3.02 | Is on the list of 'near-native accent plants' in Civano,Arizona. |
http://66.102.7.104/search?q=cache:z3Ja1mMF_SYJ:www.civano1.com/pages /documents/LandscapeGuidelines.pdf+Dasylirion+acrotriche+invasive&hl=en&gl=us&ct=clnk&cd=1 |
| 3.03 | No evidence | |
| 3.04 | No evidence [Listed on Official Regulatory List For: Arizona Department of Water Resources - as an accent plant with low water use/ drought tolerance that is not invasive.] |
http://66.102.7.104/search?q=cache:aIabrsIODzQJ:www.water.az.gov /dwr/content/Find_by_Program/Drought_and_Conservation/LowWaterPlant Lists/SantaCruzAMA/Final_SCAMA_Plant_list_with_new_cover.pdf+ Dasylirion+acrotriche+invasive&hl=en&gl=us&ct=clnk&cd=2 |
| 3.05 | No evidence [D. wheeleri is a native congener recommended for plantings in place of invasive specesi such as fountain grass in the Sonoran desert]. | http://www.desertmuseum.org/invaders/invaders_fountaingrass.htm |
| 4.01 | The leaf margins have small recurved spines. |
(1)http://www.desert-tropicals.com/Plants/Agavaceae/Dasylirion_acrotriche.html
(2)http://www.landscapemart.com/lvl.php?pd1=shpid&pd1pid=dasacr &pd2=shlist&pd2ord=d&pd2type=bn&pd2ord=d |
| 4.02 | No evidence | |
| 4.03 | No evidence | |
| 4.04 | Probably not - succulent leaves with spines on the margins. (1) '...The shrubs least preferred by goats were not affected (A. pringlei, Gutierrezia sarothrae and Dasylirion wheeleri), while preferred browse …' - [D. wheeleri is very similar to D. acrotrichum and probably is not preferred by goats either.] | (1)Influence of Spanish goats on vegetation and soils in Arizona chaparral . By: Severson, K. E.; Journal of Range Management 44 (2), 1991, p.111-117 (Journal article) |
| 4.05 | No evidence | |
| 4.06 | The following two speceis of fungi were listed to be associated with D. acrotrichum, however there is no evidence that they are of economic importance - Phomopsis gloriosa and Metasphaeria dasylirii. | Farr, D.F., Rossman, A.Y., Palm, M.E., & McCray, E.B. (n.d.) Fungal Databases, Systematic Botany & Mycology Laboratory, ARS, USDA. Retrieved June 29, 2006, from http://nt.ars-grin.gov/fungaldatabases/ |
| 4.07 | No evidence | |
| 4.08 | Although the plant is a succulent, the accumulation of dead leaves might pose a fire hazard. (See photo) |