Agrostis sandwicensis Hillebr.

synonyms: Agrostis rockii, Agrostis fallax


no known common names


Info

Subfamily: Pooideae
Genus etymology: Agrostis the ancient Greek name for herbacous plants in general, literallly "field / pasture". Its later use in plant names is reserved for grasses and there are many grass genera suffixed with Agrostis
Species etymology: sandwicensis = from the Sandwich islands (Hawaii)
Photosynthetic type: C3 (cool season)
Nativity: endemic

Map

 Distribution of Agrostis sandwicensis in Hawaiʻi.
 Distribution of Agrostis sandwicensis in Hawaiʻi.

Inflorescence

Agrostis sandwicensis Inflorescence
Agrostis sandwicensis Inflorescence

Plant

Agrostis sandwicensis Plant
Agrostis sandwicensis Plant
Agrostis sandwicensis Plant
Agrostis sandwicensis Plant
Agrostis sandwicensis Plant

Spikelets

Agrostis sandwicensis Spikelets
Agrostis sandwicensis Spikelets
Agrostis sandwicensis Spikelets
Agrostis sandwicensis Spikelets

Landscape

Agrostis sandwicensis Landscape
Agrostis sandwicensis Landscape
Agrostis sandwicensis Landscape
Agrostis sandwicensis Landscape

Collar

Agrostis sandwicensis Collar
Agrostis sandwicensis Collar

Leaf

Agrostis sandwicensis Leaf
Agrostis sandwicensis Leaf

Description

Erect, cespitose perennials; culms solitary or a few clustered together, 15-30 cm tall, glabrous. Sheaths with margins overlapping, glabrous; ligule membranous, 2-3 mm long, margins erose, apex rounded to acute; blades linear, usually 5-10 cm long, 1-2 mm wide near base, scabrous, margins often becoming involute upon drying, apex acuminate. Inflorescences paniculate, terminal, cylindrical, 5-12 cm long, often not fully emergent from the subtending sheath, the branches stiffly ascending and closely appressed to the rachis, clothed with spikelets from apex to base, glabrous to densely scabrous; spikelets numerous, slightly laterally compressed, occurring only on upper 2/3 of branches, rachilla vestigial, apex modified into a set of bristles, callus laterally subtended by a small tuft of hairs on each side; glumes 2, often tinged purple, 3-4.5 mm long, unequal, entirely enclosing the floret, scabrous on and near the midrib, glabrous toward margins, second glume 0.5-1 mm shorter than first glume, distinctly keeled and scabrous, surface glabrous to distinctly scabrous, nerves obscure, apex acuminate; lemma chartaceous to membranous, 2-3 mm long, 7-nerved, the central nerve separating c.a. 1/3 above base as an awn, the awn 0.5-2.5 mm long, slightly geniculate, usually not exceeding apex of lemma, marginal nerves not always extending to apex, glabrous, scabrous on upper 1/2 of lemma where nerves are raised, callus subtended by a tuft of hairs on either side of base of lemma margin, apex rounded to acute, usually 4 nerves prolonged as short teeth, awn geniculate, 3-4 mm long, slightly scabrous; palea vestigial, present as a membranous flap ca. 0.5 mm long. Caryopsis brown, cylindrical, 1-1.5 mm long, 0.1-0.3 mm wide.
(Description source: O’Connor, P.J. 1990. Poaceae, pp. 1481–1604. In: Wagner W.L., Herbst D.R. & Sohmer S.H. (eds.)., Manual of the flowering plant of Hawaiʻi. Vol. 2. University of Hawaii Press & Bishop Museum Press, Honolulu )