Digitaria fuscescens (C.Presl) Henr., Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

English: Y grass, yellow crab grass

Hawaiian: creeping kūkaepua‘a

Habit:  grass

Description:  "Annuals; culms ascending from a creeping base, 4-30 cm tall.  Sheaths glabrous, rarely with scattered hairs; ligule 0.5-2 mm long, truncate, erose; blades 1-5 cm long, 1-4 mm wide.  Inflorescence composed of 2 (3) digitate racemes, the racemes 1-7 cm long; spikelets ternate on a ribbon-like winged rachis, narrowly ovate-elliptic, 1.2-1.6 mm long; first glume a minute hyaline rim or absent, second glume as long as the spikelet, (3) 5-nerved, glabrous; first lemma as long as the spikelet, 7-nerved, glabrous; second lemma yellowish to brownish, as long as the spikelet, apex often bluish at anthesis, acuminate; palea enclosed within lemma, and similar in texture and color to it.  Caryopsis ellipsoid, pale brown"  (Wagner et al., 1999; p. 1531).

Description from GrassBase.

Habitat/ecology:  "Pioneer of sandy or rocky soils in humid areas; forests, dunes, cultivated areas, disturbed sites, roadsides.  0-970 m altitude. Weed of perennial crops, rice, vegetables and disturbed areas."  (Waterhouse & Mitchell, 1998; pp. 65-66).  In Hawai‘i, "forming mats in disturbed sites in grasslands, mesic shrubland and  mesic forest, 10-520 m" (Wagner et al., 1999; p. 1531).  In Fiji, "now widespread from sea level to 970 m.  It is a weed of cultivation, found along roadsides, in waste places, on open hillsides, and on sandy flats above beaches; it also occurs in dry forest, forming mats in open places, and it has become naturalized along forest trails" (Smith, 1979; pp. 323-324).  "Uncommon in dry sunny areas" (Whistler, 1988; p. 50).

Propagation:  "Seeds dispersed by water and birds.  Vegetative propagation from stolon fragments." (Waterhouse & Mitchell, 1998; pp. 65-66).

Native range:  India, southeastern Asia and Indonesia (Wagner et al., 1999; p. 1531). Fosberg et al. (1987; p. 37) list as native.

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Cook Islands Southern Cook Islands	‘Atiu Island		McCormack, Gerald (2011)
Federated States of Micronesia Chuuk Islands	Weno (Moen) Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 37)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 37)
Federated States of Micronesia Pohnpei Islands	Pohnpei Island	native	Herrera, Katherine/Lorence, David H./Flynn, Timothy/Balick, Michael J. (2010) (p. 56)
Federated States of Micronesia Yap Islands	Yap (Waqab) Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 37)
Fiji Fiji Islands	Kandavu Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324) Voucher cited: DA 9073
Fiji Fiji Islands	Koro Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324)
Fiji Fiji Islands	Mango Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324)
Fiji Fiji Islands	Matuku Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324)
Fiji Fiji Islands	Mbatiki Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324)
Fiji Fiji Islands	Moala Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324)
Fiji Fiji Islands	Moturiki Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324)
Fiji Fiji Islands	Ngau Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324)
Fiji Fiji Islands	Ovalau Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324) Voucher cited: DA 1362
Fiji Fiji Islands	Totoya Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324)
Fiji Fiji Islands	Vanua Levu Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324) Vouchers cited: DA L.15609, DA 8791, DA 11771
Fiji Fiji Islands	Vanua Mbalavu Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324)
Fiji Fiji Islands	Viti Levu Island	introduced invasive	Smith, Albert C. (1979) (pp. 323-324) Vouchers cited: DA 8238, DA 8192, Smith 9615, Smith 9601, DA 7883, DA 7926, DA 3582, DA 3963, DA 2404
French Polynesia Society Islands	Raiatea (Havai) Island	introduced invasive	Welsh, S. L. (1998) (p. 334)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1531) Voucher cited: Hitchcock 14186 (BISH)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced	Wester, Lyndon (1992) (p. 121)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced	Wester, Lyndon (1992) (p. 121)
State of Hawaii Hawaiian Islands	Maui Island	introduced	Wester, Lyndon (1992) (p. 121)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced	Wester, Lyndon (1992) (p. 121)
State of Hawaii Hawaiian Islands	Ni‘ihau Island	introduced	Wester, Lyndon (1992) (p. 121)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced	Wester, Lyndon (1992) (p. 121)
Palau Palau (main island group)	Babeldaob Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 37)
Palau Palau (main island group)	Babeldaob Island		Beleu National Museum (Republic of Palau. Koror.) (1982) (voucher ID: BNM 3179) Taxon name on voucher: Digitaria fuscescens (Presl.) Henr.
Palau Palau (main island group)	Koror Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 37)
Palau Palau (main island group)	Koror Island	native	Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar (2003) (p. 97)
Philippines Philippine Islands	Philippine Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Samoa Western Samoa Islands	Western Samoa Islands		Whistler, W. A. (1988) (p. 50)
Tonga Tonga Islands	Tonga Islands		Whistler, W. A. (1988) (p. 50)
Vanuatu New Hebrides Islands	Vanuatu (Republic of)		Swarbrick, John T. (1997) (p. 91)
Wallis and Futuna Wallis and Futuna (Horne) Islands	Wallis and Futuna Islands		Whistler, W. A. (1988) (p. 50)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
China China	China (People's Republic of)		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 44)
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Malaysia Malaysia	Malaysia (country of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Singapore Singapore	Singapore (Republic of)		Waterhouse, D. F. (1993) (p. 65)
Singapore Singapore	Singapore (Republic of)	native	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 34) Common
Thailand Thailand	Thailand (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Vietnam Vietnam	Vietnam (Socialist Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
British Indian Ocean Territory Chagos Archipelago	Diego Garcia Island	introduced invasive	Whistler, W. Arthur (1996) (p. 24)

Additional information:
Additional online information about Digitaria fuscescens is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Digitaria fuscescens as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Digitaria fuscescens may be available from the Germplasm Resources Information Network (GRIN).

References:

Beleu National Museum (Republic of Palau. Koror.). 1982. Voucher specimen #BNM3179(Timberlake, J. 3179).

Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. 2009. A checklist of the total vascular plant flora of Singapore: native, naturalised and cultivated species. Raffles Museum of Biodiversity Research, National University of Singapore. 273 pp.

Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce. 1987. A geographical checklist of the Micronesian monocotyledonae. Micronesica 20:1-126.

Hafliger, Ernst/Scholz, Hildemar. 1980. Grass weeds, vol. 1. CIBA-GEIGY Ltd., Basle, Switzerland. 142 pp. + plates.

Herrera, Katherine/Lorence, David H./Flynn, Timothy/Balick, Michael J. 2010. Checklist of the vascular plants of Pohnpei with local names and uses. Allertonia, in press. National Tropical Botanical Garden, Lawai, Hawai‘i. 146 pp.

McCormack, Gerald. 2011. Cook Islands Biodiversity Database, Version 2007.2. Cook Islands Natural Heritage Trust, Rarotonga.

Smith, Albert C. 1979. Flora Vitiensis nova: a new flora of Fiji. National Tropical Botanical Garden, Lawai, Kauai, Hawaii. Volume 1. 494 pp.

Space, James C./Waterhouse, Barbara/Miles, Joel E./Tiobech, Joseph/Rengulbai, Kashgar. 2003. Report to the Republic of Palau on invasive plant species of environmental concern. USDA Forest Service, Honolulu. 174 pp.

Swarbrick, John T. 1997. Weeds of the Pacific Islands. Technical paper no. 209. South Pacific Commission, Noumea, New Caledonia. 124 pp.

U.S. Dept. Agr., Agr. Res. Serv. 2011. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu. 1919 pp. (two volumes).

Waterhouse, B. M./Mitchell, A. A. 1998. Northern Australia Quarantine Strategy: weeds target list. Second edition. Australian Quarantine & Inspection Service, Miscellaneous Publication No. 6/98. 110 pp.

Waterhouse, D. F. 1993. The major arthropod pests and weeds of agriculture in Southeast Asia. The Australian Centre for International Agricultural Research, Canberra. 141 pp.

Welsh, S. L. 1998. Flora Societensis: A summary revision of the flowering plants of the Society Islands. E.P.S. Inc., Orem, Utah. 420 pp.

Wester, Lyndon. 1992. Origin and distribution of adventive flowering plants in Hawai‘i. In: Stone, Charles P.; Smith, Clifford W. and Tunison, J. Timothy. Alien plant invasions in native ecosystems of Hawaii: Management and Research. University of Hawaii, Cooperative National Park Research Studies Unit, Honolulu. University of Hawaii Press. .

Whistler, W. A. 1988. Checklist of the weed flora of western Polynesia. Technical Paper No. 194, South Pacific Commission, Noumea, New Caledonia. 69 pp.

Whistler, W. Arthur. 1996. Botanical survey of Diego Garcia, Chagos Archipelago, British Indian Ocean Territory. Isle Botanica. 49 pp.