Cook Islands Biodiversity & Natural Heritage
 

Digitaria stenotaphrodes

Thickhead Grass

Multimedia & Additional Resources

Type Description Download
Open this image in pop-up window Image: Plant and detail of spike 51KB
Open this image in pop-up window Image: Compare: Digitaria pacifica (Line Islands) 59KB

General Information

COMMON NAMES: Thickhead Grass

TRADITIONAL NAMES: Vayavaya (PK)

GLOBAL DISTRIBUTION: NATIVE Carolines - Tuvalu - Pukapuka/Suwarrow - Tuamotu (atolls only)

COOK ISLANDS STATUS: Native; N.Group only - very rare (PK and SW only); Land

SIGNIFICANCE LIST: ; Nationally endangered - seriously

KEY FEATURES: An ascending, tufted grass, to 70cm high, with a cylindrical flowering head; spikes 4-6, erect, parallel, ~joined at base, 6-15cm; spike-midrib distinctly winged; SPIKELET lanceolate (c.4:1) with second glume about 25% of spikelet length. LEAVES to 25x1cm.

SIMILAR SPECIES: Line Islands Thickhead-Grass (Digitaria pacifica - not yet known in the Cook Islands) has spikes to 10 (vs to 6); spikelet ovate - c.2:1 L:B (vs lanceolate - c.4:1 L:B); second glume round and 10% length of spikelet (vs arrowlike and 25% of spikelet).

Enlarged Image of 'Digitaria stenotaphrodes'

Cook Islands Distribution

View Distribution Map View Distribution Map

Southern Group: -    Makatea: -
RR 
MG
AT
MK
MT
AK
PL
TK
MN
-
-
-
-
-
-
-
-
-

Northern Group: Present
TN 
MH
RK
PK
NS
SW
-
-
-
+
-
+

Key to Symbols

Scientific Taxonomy

Digitaria stenotaphrodes (Nees)
SYNONYMS: Syntherisma pelagica

TAXONOMY: PLANTAE; ANTHOPHYTA (=Angiospermae); LILIOPSIDA (=Monocotyledones); COMMELINIDAE; Cyperales; POACEAE

More Information

SIGNIFICANCE NOTES -
BIODIVERSITY: Nationally endangered - seriously. Comment: Known from one plant on Pukapuka and one plant on Suwarrow.

Vouchers & References

Vouchers:
Pukapuka: specimen+photo, Motu Kō on track entering eastern forest from runway, 2/2004, G.McCormack with ID as Digitaria stenotaphrodes - second glume 25% of lanceolate spikelet. Suwarrow: specimen, One Tree Motu, 8/1993, B.Sykes.

References:
None recorded.

Data Update History (information):
zTX, zB02, zM05a, zD02, zupD04a

Web Resources

Citation Information

McCormack, Gerald (2007) Cook Islands Biodiversity Database, Version 2007.2. Cook Islands Natural Heritage Trust, Rarotonga. Online at http://cookislands.bishopmuseum.org. Copy citation to system clipboard
Please refer to our use policy.


Search Biodiversity Database Biodiversity Database

More Options | Help
My List My List

 

 


Copyright © 2007 (July) The Cook Islands Natural Heritage Trust, all rights reserved.
Copyright & Use Policy