Costus woodsonii Maas, Costaceae

Click on an image for links to BIGGER PICTURES

Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 11 (Go to the risk assessment)

Common name(s): [more details]

English: Indian-head ginger, red cane

Hawaiian: ‘awapuhi ‘inikini po‘o

Habit:  herb

Description:  "Leafy shoots 6-12 feet tall, glabrous.  Leaves stiff, often ± deflexed; blades elliptic, ovate, or ± obovate, 3-10 x 1.5-4.25 inches, base cordate.  Inflorescence terminal on leafy stems, globose, ovoid, or cylindrical, 1-4 inches long, often producing axillary shoots, elongating in fruit; bracts broadly ovate, red.  Flower calyx 0.25-0.6 inch long; corolla lobes orange to red-orange; labellum oblong, 0.75-1.2 x 0.5-0.75 inches, yellow, lateral lobes inrolled, tubular, often orangish; stamens yellow, 1.25 inches long.  Fruit ellipsoid, 0.3-0.5 inch long"  (Staples & Herbst, 2005; p. 652).

"The leaves are spirally arranged, thick, and dark green, the bracts dark red, and the flowers red-orange" (Daehler & Baker, 2006; p. 7).

"In Hawai‘i, C. woodsonii has long been confused with C. spicatus (N. Jacquin) Swartz, which has slightly larger leaves that are hairy along the midrib on the upper side, greenish red primary bracts that eventually shred at the margin, and slightly larger flowers with a much larger labellum"  (Staples & Herbst, 2005; p. 653).

Habitat/ecology:  In Hawai‘i (O‘ahu), naturalized in many parts of Lyon Arboretum (Daehler & Baker, 2006; p. 7).  "Its rhizomes are robust and invasive, and once established they are difficult to remove.  This aggressive species grows in full sun, even in beach areas on sandy soils, but truly does its best where shade, ample moisture, and a deep, fertile soil are available"  (Staples & Herbst, 2005; p. 653).

Propagation:  "This species spreads locally by plantlets that develop on old inflorescences. It has also spread to other areas of the [Lyon] Arboretum, some quite remote from the original planting, suggesting reproduction by seeds" (Daehler & Baker, 2006; p. 7).  Local spread is by rhizome division (Staples & Herbst, 2005; p. 653).

Native range:  Costa Rica, Nicaragua, Panama, Colombia (GRIN).

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	Rarotonga Island	introduced invasive cultivated	McCormack, Gerald (2013)
French Polynesia Marquesas Islands	Ua Huka (Huahuna, Uahuka) Island	introduced cultivated	Lorence, David H./Wagner, Warren L. (2013)
State of Hawaii Hawaiian Islands	Kaua‘i Island		Bishop Museum (U.S.A. Hawaii. Honolulu.) (1985) (voucher ID: BISH 501450) Taxon name on voucher: Costus woodsonii Maas
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Oppenheimer, Hank L. (2004) (p. 11) East Maui. Voucher cited: Oppenheimer H60204 (BISH)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1381)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive cultivated	Daehler, Curtis C./Baker, Raymond F. (2006) (p. 7) Voucher cited: C. Daehler 1307 (BISH)
Marshall Islands Ralik Chain	Kwajalein (Kuwajleen) Atoll	introduced cultivated	Whistler, W. A./Steele, O. (1999) (p. 105)
Palau Palau (Belau ) (main island group)	Ngerkebesang Island	introduced cultivated	Space, James C./Lorence, David H./LaRosa, Anne Marie (2009) (p. 6) Voucher: Lorence 9721 (PTBG, BNM)
Palau Palau (Belau ) (main island group)	Ngerkebesang Island		National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2008) (voucher ID: PTBG 14) Taxon name on voucher: Costus woodsonii Maas

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Central America Central America (Pacific rim)	Costa Rica (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Nicaragua (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Central America Central America (Pacific rim)	Panama (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Singapore Singapore	Singapore (Republic of)	introduced cultivated	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 29) Cultivated only
South America (Pacific rim) South America (Pacific rim)	Colombia	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Control:  If you know of control methods for Costus woodsonii, please let us know.