CHAETOPHORALES 



69 



*Trentepohliaceae : Trentepohlia (after J. F. Trentepohl) (Chroo- 

 lepus). Fig. 49. 



The species grow as epiphytes or on stones in damp tropical 

 and subtropical regions, but they will also grow under temperate 



ALOA 



GELATINE 



COTTON WOOL 



Fig. 49. Trentepohlia. 

 tabulae, cell structure. 



A, B, T. montis -tabulae with pectin caps. C, T. montis- 

 c = cap, i = innermost layer of cell wall. D-F, types of 

 chloroplast. G, chloroplast in T. lolithus. H, I, T. umbrina, fragmentation of 

 prostrate system. J, threads of T. aurea bearing sporangia {s). K, T. umbrina, 

 sporangia. L, M, two stages in the development of the "funnel" sporangium in 

 T. annulata. N, graph showing decreasing water contents of Trentepohlia, 

 gelatin and cotton-wool on drying. O, P, T. umbrina, detachment of stalked 

 sporangium, i.r. = inner, o.r. = outer thickening of sporangial septum. Q, mature 

 "funnel" sporangium, T. annulata. R, S, gametangia of T. umbrina. (A-G, J, 

 L, M, O-Q, after Fritsch; H, I, K, R, S, after Oltmanns; N, after Rowland.) 



conditions if there is an adequate supply of moisture. The threads 

 have a characteristic orange-red colouring due to the presence of 

 y^-carotin which is said to be a food reserve accumulated during 

 periods of slow growth, but if this is so it would be expected 

 that it should accumulate under favourable conditions of rapid 



