Test on Grass Species Morphology and Identification

Question 1: Paspalum atratum spikelets are dorsally compressed.

A. Ano

B. Ne

Explanation: The study materials state under 'Paspalum atratum' that 'Spikelets elliptic, or obovate; dorsally compressed; plano - convex;'.

Question 2: Which of the following statements accurately describe a key habit difference between Cynodon dactylon and the other two specified Cynodon species (C. nlemfuensis and C. plectostachyus) based on the provided study materials?

A. Cynodon dactylon possesses elongated rhizomes, a feature absent in both C. nlemfuensis and C. plectostachyus.

B. Cynodon dactylon has culms that are typically 30-60 cm long, similar to C. nlemfuensis but longer than C. plectostachyus.

C. Cynodon dactylon's ligule is an eciliate membrane, unlike the ciliolate membrane found in C. nlemfuensis.

D. Cynodon dactylon's leaf-blades are primarily conduplicate, while the other two species always have flat leaf-blades.

Explanation: The study materials state that Cynodon dactylon has 'Rhizomes elongated', whereas both Cynodon nlemfuensis and Cynodon plectostachyus are described as having 'Rhizomes absent'. This is a clear distinguishing feature in their habit. Option 1 is incorrect because C. dactylon culms are 8-40 cm long, and C. plectostachyus culms are 30-90 cm. Option 2 is incorrect because C. dactylon's ligule is a ciliolate membrane, as is C. nlemfuensis', while C. plectostachyus has an eciliate membrane. Option 3 is incorrect because C. dactylon leaf-blades can be flat or conduplicate, but C. nlemfuensis and C. plectostachyus only have flat leaf-blades, making the statement about 'always' incorrect as a point of difference in that direction, and C. dactylon's leaf-blades are not 'primarily' conduplicate over flat according to the text.

Question 3: The lower glume of Cynodon dactylon has lateral veins.

A. Ano

B. Ne

Explanation: The study materials state that the 'Lower glume lateral veins absent' for Cynodon dactylon.

Question 4: Which of the following characteristics accurately describe the glumes of *Cynodon plectostachyus*?

A. Both lower and upper glumes are ovate and have lateral veins absent.

B. The lower glume is 0.5 length of the upper glume, and the upper glume is 0.1 – 0.2 length of the adjacent fertile lemma.

C. The glumes are deciduous and thicker than the fertile lemma.

D. The lower glume is lanceolate and 1 length of the upper glume.

Explanation: According to the study materials, for *Cynodon plectostachyus*, the lower glume is ovate and lateral veins are absent, and the upper glume is also ovate with lateral veins absent. The lower glume is 0.5 length of the upper glume, and the upper glume is 0.1 – 0.2 length of the adjacent fertile lemma. The glumes are persistent (not deciduous) and thinner than the fertile lemma. The lower glume is ovate, not lanceolate.

Question 5: Lolium multiflorum spikelets are dorsally compressed.

A. Ano

B. Ne

Explanation: The study materials state that Lolium multiflorum spikelets are laterally compressed, not dorsally compressed.