16 ON BPHJEBOCOMA, A NEW GENUS OF CABYOPHYLLACEiE. 



the complete one made by Drs. Hooker and Thomson, at Aden, in 

 1847 & 1851. 



Chab. Gen. — Calyx 5-partitus, in fructu persistens, laciniia mu- 

 cronatis ovatis marginibus serratis, florum sterilium demum 

 longe setaceis. Petala 5, subhypogyna, fere perigyna, erecta, 

 ovata, obtusa, persistentia. Stamina 5, dentibus annuli perigyni 

 alterna, in annulum perigynum inserta. Anther a biloculares, 

 ovatae. Ovarium nniloculare, biovulatnm, placenta supra ovula 

 elongata. Stylus brevis ; stigma bifidum, lobis fimbriatis. 

 TTtriculus cbartaceus, indehiscens, abortivo monospermus. 

 Semen campylotropum subrotundum. Embryo curvatus albu- 

 men farinaceum includens. 



Fruticulus regionis aridce Arabics Felicis " Tehama" dietce, habitu 

 Gymnoearpidos, exstipulatus ; folia fasciculata, carnosa; glo- 

 meruli post antliesin in capitula setigera transformantes. 



SpHjERocoma Hookeri. — Caule erecto lignoso ramoso, cortice glauco ; 

 foliis in nodis oppositis caulinis fascieulatis carnosis teretibus apice 

 obtusis, basi attenuatis ; glomerulis pedunculatis ebracteatis, floribus 

 dense aggregatis ; sepalis ovatis concavis mucronati3, florum sterilium 

 linearibus, in fructu setaceis, setis integris ; capsula calyce et corolla 

 squamis persistentibus inclusa. 



Fruticulus 2-pedalis, ramosus, glaberrimus, glaucus ; caulis nodis oppo- 

 sitis foliosis. Folia 6-10'". Glomeruli fusci 1-3'", pedunculis 1-1 J"' 

 ereetis; bracteis 1-2 sepaloideis. Utriculus parvus, subchartaceus. 



In the dried plant, many of the leaves seem as if their upper 

 part was covered by a loose membranaceous calyptra. This ap- 

 pearance is evidently caused by the rapid drying of the more 

 succulent upper portions of the leaves having occasioned a shrivel- 

 ling of the epidermis, which becomes detached from the subjacent 

 tissue. 



Tab. III. fig. 1, leaf; 2, head of flowers; 3, flower; 4, the same laid 

 open ; 5, stamen ; 6, pistil ; 7, vertical, and 8, transverse section of ovary ; 

 9, head of fruit; 10, sterile and fertile flowers; 11, utriculus; 12, seed; 

 13, vertical section of seed; 14, embryo. 



All the figures, except 2 and 9, are more or less magnified. 



