Plate 160.— RHABDOTHAMNUS SOLANDRI. 



Family GESNERACEiE.] [Genus RHABDOTHAMNUS, A. Cunn. 



Rhabdothamnus Solandri, A. Cunn. Precur. n. 385 ; Cheesem. Man. N.Z. Fl. 562. 



The family GesneracecB reaches its southern limit in New Zealand, where it 

 is represented by the subject of this plate, a monotypic genus allied to the Lord 

 Howe Island Negria and the New Caledonian Coronanthera. All three are not 

 very far removetl from the huge Malayan and Pacific genus Cyrtandra, of which 

 almost every island in Polynesia possesses its peculiar species. 



Rhabdothamnus Solandri was originally discovered by Banks and Solander in 

 Mercury Bay (or Opuragi, as Solander called it) during Cook's first visit to New 

 Zealand. It was fully described and figured in Solander's manuscript " Primitiee 

 Florae Novse Zelandise " under the name (which was never actually published) of 

 Columnea scabrosa. It does not seem to have been noticed again until Allan 

 Cunningham's first visit in 1826, when he gathered it in the Bay of Islands and 

 Whangaroa districts. Subsequent research has proved that it is an abundant plant 

 all through the northern portion of the North Island, from the North Cape south- 

 wards, but that it becomes rare and local to the south of Taranaki, although it 

 has been recorded from various localities almost as far south as Cook Strait. Its 

 altitudinal range is from sea-level to about 2,000 ft. 



R. Solandri is a much-branched shrub seldom more than 4 ft. or 5 ft. high, 

 everywhere rough to the touch from a covering of minute short and stiff conical 

 hairs. It is usually found on the shaded sides of wooded ravines, where the forest 

 is comparatively open and the soil dry and often shingly. It is also frequently 

 seen on wooded declivities by the seashore. It has slender spreading often inter- 

 twined branches, and dull-green broadly ovate or orbicular coarsely toothed leaves. 

 The flowers are decidedly handsome, f in. to 1 in. in length, orange with red stripes, 

 and are produced in succession during the major portion of the year. 



The pollination of RhabdofJiamnus has been described in detail by Mr. Petrie 

 in a paper printed in the " Transactions of the New Zealand Institute " (vol. xxxv, 

 p. .321). He points out that the flowers are proterandrous, the stigma being quite 

 immature when the anthers are discharging their pollen, thus making the 

 fertilization of the flower by its own pollen practically impossible. Further, 

 there is a curious change in the position of the anthers after they have wholly or 

 partly shed their pollen. When dehiscence commences they are so situated that 

 a bird thrusting its head into the flower cannot avoid being plentifully dusted with 

 pollen. At a later period the anthers move until they are in contact with the lower 

 lip of the corolla, the now mature stigma occupying almost the same position that 

 the anthers previously held. It follows from the above that fertilization is probably 

 effected by birds carrying the pollen from recently expanded flowers and depositing 

 it on the stigmas of much older flowers. 



Plate 160. Rhabdothamnus Solandri, drawn from specimens collected on the Waitakerei Eanges, 

 near Auckland. Fig. 1, portion of leaf, showing its covering of short conical hairs (x 5) ; 2, hairs 

 still further enlarged ; 3, calyx, with ovary and style (x 2) ; 4, corolla laid open (x 2) ; 5, anthers 

 (x 6) ; 6, ovary (x 4) ; 7, transverse section of ovary (x 4) ; 8, fruit (x 3). 



