PHANEROGAMS — PROFESSOR BAYLEY BALFOUR. 313 



3. S. verticellata, Beauv. Agrostog. 51 ; Kunth Enum. i. 152 ; Reichb. 

 Ic. Flor. Germ. i. t. 47. 



Panicum verticillatum, Linn. Sp. 82 ; Trin. Spec. Gram. ii. t. 202. 

 P. respiciens, Hochst. in herb. Schimp. Abyss, sect. iii. n. 1654. 

 Pennisetum respiciens, Ach. Rich. Tent. Flor. Abyss, ii. 379. 



Socotra. Near Galonsir. B.C.S. n. 53. 

 Distrib. Tropical weed of cultivation. 



6. CENCHRUS. 



Cenchrus, Linn. Gen. n. 1149, pro parte; Benth. et Hook. Gen. PL iii. 1105. 

 A small genus of wide distribution in the tropics of the world. 



C. Schimperi, Hochst. et Steud. in herb. Schimp. Arab. sect. i. n. 796. 



C. montanus, Nees in Royle Illustr. Himal. 416, absque descr. fide Steud. Syn. Glum. i. 111. 



C. tripsacoides, R. Br. in App. Salt Abyss, (fide Steud.). 



C. bulbifer, Hochst. in herb. Schimp. Abyss, ed. Hohenack. n. 2196. 



Socotra. Abundant, B.C.S. nn. 66, 123, 235. 

 Distrib. Tropical Africa, Arabia, and India. 



This plant occurs in both a dwarf and a large state. The dwarf, which is 

 the typical Arabian form, is common on Socotra. 



7. PENNISETUM. 



Pennisetum, Pers. Syn. i. 72 ; Benth. et Hook. Gen. PI. iii. 1105. 



A considerable genus with its headquarters in Africa, but extending through 

 the tropics of both old and new worlds. One of the Socotran plants is cos- 

 mopolitan in the tropics, the other is an old world form. 



1. P. dichotomum, Delile Fl.^Egypt. 15, t. 8, f. i.; Kunth Enum. i. 161. 

 Nom. Vern. Kassade (Schweinf.). 



Socotra. Common. B.C.S. nn. 232, 251. Schweinf. n. 456. 



Distrib. North-east tropical Africa and south-west Asia. 



A very variable species in its flowering spikes, which has given rise to a 

 copious synonymy. Delile's plant may be taken as a centre around which a 

 number of other forms ' group themselves. Our plant differs from the type in 

 the pubescent rhachis of the flower-spike, and it resembles, according to 

 Schweinfurth, P. spectabilis, Fig. and De Not. (Agrostogr. ^Egypt. Frag. i. 248), 

 from which, however, it is excluded by the length of the glume. With P. 

 tiberiades, Boiss. (Diagn. i. 13, 43), it agrees well, but from it again its hairy 

 rhachis differentiates it. 



2. P. cenchroides, Pers. Syn. i. 72 ; Kunth Enum. i. 162 ; Ach. Rich. 

 Tent. Flor. Abyss, ii. 384. 



TRANS. ROY. SOC. EDIN. VOL. XXXI. 2 R 



