978 DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



Stem and Branches. 



Specimens of the stem were received, both dry and preserved in spirit. They vary 

 in diameter from l^ths to l T %ths of an inch. The dry specimens, equally with those 

 preserved in spirit, have a cork-like surface, which is profusely furrowed by deep branching 

 grooves (Plate IV. figs. 1 and 2). In the dry specimens, the cork layer has shrunk so as 

 to lay bare at the extremities the underlying hard structures of the stem. In a portion 

 of dry stem l T 6 & ths of an inch in diameter, the cork layer was ^ths of an inch in thickness. 

 The structure of the stem has been further illustrated in Plate V. figs. 2 and 3, repre- 

 senting transverse sections, and fig. 4, a longitudinal section. 



The branches are opposite. Their surface is nearly smooth, and the cork layer is 

 thin, thus presenting a marked contrast to the stem ; and they have numerous small, 

 irregularly-shaped, pale (greyish-brown) markings. 



Juice of Root, Stem, and Branches. — On examining fresh young plants, raised in the 

 Edinburgh Botanic Garden from seeds sent from the Shire district, I found that when 

 incisions were made into the roots, stem, or branches, there exuded a considerable 

 quantity of juice. From each of these parts it is acid and very bitter, and at first quite 

 clear and almost colourless. The juice of the stem is, however, very sticky, and in a 

 short time it becomes milky ; but that from the root and branches remains unadhesive 

 and non-opalescent. 



Through the kindness of Mr John Moir, I have obtained from Africa a small quantity 

 of the exuded juice from the stem of a growing plant. It consists of a slightly opalescent, 

 bitter, and acid fluid, in which there is a mass of a plastic caoutchouc-like substance. 



Leaves. 

 The leaves are entire, and generally oval acuminate, though occasionally they 

 are ovate or obovate and shortly acuminate. The largest of those sent from East 

 Central Africa is 5 T 2 ^ths by 2-^gths of an inch, and the smallest l T 9 6 ths by i\ths of an 

 inch. They are opposite, and have usually short petioles, but those attached to the 

 extremities of branches are sessile or almost so. Both surfaces, the lower rather more so 

 than the upper, are well covered with short fine hairs, which are most abundant along 

 the veins and margins. The petioles, flower bracts, and terminal branches are also pro- 

 fusely hirsute (see Plate III. figs. 5 and 6). 



Flowers. 

 The flowers are grouped in terminal cymes, which sometimes contain only four 

 or five flowers, but often as many as eight or nine (see Plate III. fig. 6). In the 

 specimens in my possession, unexpanded flowers are present with expanded ones in 

 the same cyme. The calyx is gamosepalous and five-lobed, each lobe being oval 

 acuminate in the expanded flower, and almost linear in the unexpanded flower-bud ; 

 and the calyx and its lobes are covered on the outside with numerous fine hairs. 

 The corolla is gamopetalous, funnel-shaped, and five-lobed, each lobe being pro- 



