Cenchrus longispinus (Hackel) Fern.
Family: Poaceae, Tribe: Paniceae
Pertinent Synonyms & Notes (particularly those used in California; go to GRIN for other synonyms)
Cenchrus carolinianus Walt.
Pertinent Common Names (particularly those used in California; go to GRIN for other common names)
longspine sandbur
Primary Disseminule Type
spikelets surrounded by a spiny cupule
Description (diagnostics are in brown)
Disseminule consists of a cluster of 2–3(4) spikelets enclosed in a cupule of mostly fused bristles (i.e., a spiny bur). Bur is ± globose, 8.3–11.9 mm long x 3.5–6 mm wide, pubescent, base obconical. Outer bristles numerous, shorter and thinner than inner bristles, mostly terete, reflexed. Inner bristles 3.5–7 mm long x 0.5–0.9(1.4) mm wide at the base, fused for at least half their length, rigid, often grooved along the margins, purplish.
Spikelet ovate, dorsally compressed, (4)5.8–7.8 mm long x 2–3 mm wide, glabrous, acuminate, consisting of a basal sterile floret, a fertile floret, and no rachilla. Lower glume ovate, 0.8–3.8 mm long, 0.25–0.5 length of spikelet, membranous, without keel, 1-veined, apex acute. Upper glume ovate, 4–6 mm long, 0.75 length of spikelet, membranous, without keel, 3–5-veined, apex acute.
Sterile lemma ovate, 4–6.5 mm long, 0.8 length of spikelet, membranous, 3–7-veined, apex acute. Sterile palea somewhat reduced.
Fertile lemma ovate, (4)5.8–7.6(8) mm long, coriaceous, much thinner on margins, without keel, 3-veined, margins flat, apex obtuse to acute.
Fertile palea subequal to fertile lemma, coriaceous.
Caryopsis broadly ovate, dorsally compressed, 2–3.8 mm long x 1.5–2.6 mm wide, brown, embryo >0.75 length of caryopsis, hilum round, black.
Similar Species
Risk Assessment (codes in yellow or red indicate cause for concern; assessments are current as of mid-2011; click AUQP, NZBORIC, or NZBPI for access to the most recent versions of these databases and possible assessment changes)
AUQP, AUWP, NZWP, NZBORIC, NZBPI