Alloteropsis semialata, known commonly as black seed grass, cockatoo grass, donkersaad gras, swartsaadgras, tweevingergras, and isi quinti, is a
perennialgrass distributed across much of
tropical and
subtropicalAfrica,
Asia and
Australia, as well as
Papuasia and
Madagascar.[1][2][3] The genus name Allopteropsis comes from the
Greek words "allotrios", meaning "belonging to another", and "opsis", meaning appearance. The specific epithet semialata comes from the
Latin "semi" (half) and "ala" (wing), referring to the winged margins of the upper
glume.[4]
Description
This plant typically reaches 20–150 centimeters tall, growing from a short, white
rhizome.[5] The leaf blades are typically 10–50 centimeters long and 1–10 millimeters wide. The plant produces 2-flowered fertile spikelets.[6]
Variation
The species has two
subspecies including A. semialata subsp. semialata, which uses the
C4 photosynthetic pathway, and A. semialata subsp. eckloniana, which uses the
C3 photosynthetic pathway.[7] As the only plant species known to use both pathways, it is an important model for the study of the evolution of photosynthesis. There are a wide range of intermediate phenotypes, including that of
C2 photosynthesis.[8]
The species has been found in a
polyploid series with
diploid,
tetraploid,
hexaploid,
octoploid and
dodecaploid individuals. All members of the C3 subspecies are diploid and there are no diploid individuals outside of that subspecies.[9]
Ecology
The seeds of this species are an important component of the wet-season diet of many granivorous finches and parrots. The rhizomes are part of the dry-season diet of some animals.[4]