4 DR. J. D. HOOKER ON THE STRUCTURE AND 



The rhizomes in many species attain a considerable age ; but it is difficult to ascertain 

 then- duration after they have commenced flowering. Helosis seems to be capable of in- 

 definite increase ; the individual patches of the plant flowering at all or most seasons of the 

 year, and the old branches of the rhizome dying as new ones are formed. In Fliyllocoryne 

 also, the laro-e many-lobed rhizome seems perennial, and to flower at various seasons. In 

 Bhojmlocnemis and several species of Balanophora, it appears to me as if the rhizome 

 continues to increase for several years ; and then, after thro\ving up many peduncles in 

 one season, to die the following autunui. Others however, as B. involiicrata, which causes 

 oi'eat knots to form on the roots of trees, either live many years and flower perennially, or 

 else a perennial succession of young plants germinate upon the swollen root ; a mode of 

 increase suggested by the germinating specimen represented in Plate VI. fig. 8. In 

 Lophophijtum each tuber-like rhizome gives off only one or two peduncles, and the root on 

 which it grows forms a shallow cup round its base ; which I have found to be of many 

 years' gro^vtll. Cynomoriiim appears to be decidedly annual, but I have not examined a 

 sufficient number of specimens with the attachment preserved, to decide this point. 

 Langsdorffia has certainly a perennial branching rhizome, and Sareophyte a perennial 

 tuberous one. Most of the Balanophorce have lobed or branched rhizomes, which perhaps 

 die after flowering. 



In no case is the vegetation of the rhizome very rapid, in comparison with that of many 

 plants ; and especially of Fungi, with which some authors have compared them. On the 

 contrary, I believe that the growth of all the parts is very slow ; and Avith regard to Blio- 

 palocnemis and Balanophora especially, I have had many opportunities of observing that 

 the peduncle did not flower for several weeks after its protrusion from the rhizome. 



- The modes of attaclunent above indicated suggest another division of Balanophorece, 

 namely, into — 1. those in which the vascular tissue of the parasite is continuous with 

 that of the root ; 2. those in which the attachment is by means of the cellular system 

 only ; and 3. those in which bundles of vessels from the root terminate definitely in the 

 parasite, a short distance from the point of attachment ; the vascular systems of the two 

 plants forming no evident confluence. 



Of the iii-st of these classes Balanophora and Rhopalocnemis are the best examples, from 

 the great development of their vascular systems (which in some species present woody 

 zones, a cortical system, and medullary rays), and from the fact that in many instances 

 bundles of vessels appear to run in unbroken continuity from the woody system of the 

 root to the very flowers of the parasite. 



In the species of this first group, the appearance of the parasite having derived all its 

 vascular tissue from the root has given rise to the hypothesis, that the whole production 

 is an abnormal development from the root of the plant on which it grows : — thus Junghuhn 

 quotes Ti-attinick (Linnsea, iii. p. 19i) as saying of Sareophyte, " hasce parasitas degene- 

 rationes plantarum specificas, sine seminum aditu creatas, modo spontaneo genitas ; " 

 and adds (Nov. Act. Acad, xviii. Suppl. p. 205), " Mihi Balanophorarum vegetatio 

 fungosa est, originaria. Succi arborum, e quarum radicibus vivis sanisque Balano- 

 phorcB progermiuant, nimis copiosi, cm'su consueto perturbati, morphosin arboris redun- 

 dantis, ut ita dicam, retrogradam provocant, atque (directione vegetationis mutata) in 



