Front Range Seed Analysts
1998 Seed Forum Volume 12 Number 3
Grass Embryo Types
article summary by Annette Miller
I love to find articles that are many decades old yet still important reading for today's analyst. One such paper is John R. Reeder's "The Embryo in Grass Systematics" in the American Journal of Botany, November 1957 (volume 44), pages 756-768. Reeder's drawings and charts will help you to refine your knowledge of grass embryos beyond the basic corn and wheat embryo anatomy with which analysts begin.
It helps to have a feel for subfamilies and tribes in
the grass family. Reeder's article uses some outdated tribe names
and groupings. A partial list of some well known genera
and their current tribes are listed here (from Gould & Shaw's Grass
Systematics). Reeder's four-part embryo formulas are given for each group
with some exceptions listed. The formula components will be discussed
later in this article.
Subfamily: Pooideae F+FF
Tribe: Poeae
Briza, Bromus, Dactylis, Distichlis, Eragrostis, Festuca,
Lolium, Poa, Puccinellia,
Tribe: Aveneae
Agrostis, Alopecurus, Arrhenatherum, Avena, Calamagrostis,
Deschampsia, Phalaris, Phleum, Polypogon, Trisetum
Tribe: Triticeae
Agropyron, Elymus(-), Hordeum, Secale(-), Triticum
Tribe: Meliceae
Melica, Glyceria
Tribe: Stipeae
Oryzopsis, Stipa
Subfamily: Panicoideae P-PP
Tribe: Paniceae
Cenchrus, Digitaria, Echinochloa, Eriochloa, Panicum,
Paspalum, Pennisetum, Setaria
Tribe: Andropogoneae
Andropogon, Bothriochloa Miscanthus, Sorghastrum, Sorghum,Tripsacum,
Zea
Subfamily: Chloridoideae
Tribe: Eragrosteae
P+PF
Calamovilfa, Eragrostis, Eleusine, Muhlenbergia, Sporoblous,
Tridens
Tribe: Chlorideae
P+PF
Bouteloua, Buchloe, Chloris, Cynodon, Hilaria, Schedonnardus,
Spartina
Tribe: Aristideae
P-PF
Aristida
Subfamily: Oryzoideae
Tribe: Oryzeae
Oryza F+FP, Zizania F+PP
Subfamily: Arundinoideae P-PF
Tribe: Danthonieae
Danthonia, Schismus
Tribe: Arundineae
Arundo, Phragmites
Subfamily: Bambusoideae F+PP
Tribe: Bambuseae
Arundinaria
If you have done lots of grass TZ's, you may have made some of these associations in your mind. Reeder's embryo observations and classifications give weight to these tribe and subfamily associations. They even allow you to make an educated guess about a tribe classification of unknown seeds.
