544 PSWIOPSIS 



Paidlopais Berg. Myrtaceae (i). i Venezuela. Ed. fr. 



Psidium L. Myrtaceae (i). no trop. Am., W.I. Many yielded, fr., 

 e.g. P. Guajava L. , the guava. 



Psila Phil. Compositae (4). i Chili. 



Psilactis A. Gray. Compositae (3). 3 Mexico. 



Psilanthele Lindau. Acanthaceae (iv. B). 3 trop. S. Am., Jamaica. 



Psilanthus Hook. f. Rubiaceae (n. 4). 2 trop. W. Afr. 



Psilium (Cl.), a prairie formation. 



Psilobium Jack. Rubiaceae (i. 7). 2 Sumatra. 



Psilocarphus Nutt. Compositae (4). 4 \V. U.S., Chili. 



Psilocarya Torr. (Ryncospora Bff.). Cyperaceae (i). 6 Am., Austr. 



PsilocMlus Rodr. (Cleistes p.p. EP.). Orchid, (n. 2). i Brazil. 



PsUonema C. A. Mey. = Alyssum L. (Crucif.). 



Psilopeganum Hemsley. Rutaceae (i). i C. China. 



Psilostachys Hochst. (Psilotrichium P.). Amarant. (2). 4 trop. |#. 



Psilostroplie DC. (Riddellia Nutt.). Compositae (6). 6 S.W. U.S. 



Psilotaceae. Psilotales Two gen. (Psilotum, Tmesipteris) with 4 sp. 

 trop. and subtrop. The mature sporophyte has no roots, their functions 

 being performed by the branched rhiz. The aerial branches bear only 

 scale-1. in Psilotum. The sporangia are 2- or 3-loc., borne on small 

 two-lobed sporophylls. "There has been much disagreement as to 

 the morphological nature of the sporangiophores of the Psilotaceae. 

 The two chief views are the following: (i) that the whole sporangio- 

 phore is a single foliar member; (2) that it is a reduced axis bearing 

 a terminal synangium and two 1. The recent very careful researches 

 of Bovver upon the origin of the sporangiophore and synangium confirm 

 the former view" (Campbell ; see also Bower in Phil. Trans. CLXXXV, 

 1894, p. 473). 



"The fully-developed synangium (2-loc. in Tmesipteris, 3-loc. in 

 Psilotum) has the outer walls of the loculi composed of a superficial 

 layer of large cells, beneath which are several layers of smaller ones. 

 The cells composing the septa are narrow tabular ones; occasionally 

 the septum is partially absent.... Bovver regards the whole synangium 

 as homologous with the single sporangium of Lycopodium" (Camp- 

 bell). The prothallus has not been seen. 



Psilotales. The 5th class of Pteridophyta. 



Psilotrichum Blume Amarantaceae (2). 15 palaeotrop. 



Psilotum Svv. Psilotaceae. 3 trop. They are probably =t saprophy tic 

 in their habit, and have neither roots nor green L, but only green stems. 

 See fam. for details of sporangia, &c. Veg. repr. is common, small 

 gemmae being formed upon the rhiz. At first no structural differentia- 

 tion is visible in these, but apical cells are formed later. 



Psiloxylon Thou, ex Tul. (Fropiera BH.}. Flacourt. (inc. sed.). i 

 Masc. 



Psilurus Trin. Gramineae (12). i S. Eur. to Afghanistan. 



Psittacanthus Mart. (Loranthus p.p. BH.}. Loranthaceae (i). 50 trop. 

 Am. 



Psophocarpus Neck. Leguminosae (ill. 10). 5 palaeotrop. P. tetra- 

 gonolobus DC. and others cult. ed. pods. 



Psoralea L. Leguminosae (in. 6). 100 trop. and subtrop. P. esculenta 

 Pursh (N. Am. prairie turnip) has ed. tuberous root. 



