PITURI 517 



Pistia L. Araceae (vin). i trop. and suhtrop., P. Stratiotes L., a 

 floating water-plant, rarely anchored by its roots, and often blown 

 about by wind. It is of sympodial structure, but the internodes remain 

 short and bear a rosette of large 1. ; these sleep at night, moving up- 

 wards from the nearly horiz. clay position. The continuation shoots 

 of the sympodium are axillary, but beside each 1. arises a stolon which 

 grows out along the water and gives rise to a new pi. The infl. is 

 small and monoec. ; above is a whorl of S fls., each with a synandrimn 

 of 2 sta.; below is a ? fl. of i cpl. Both are naked. P. is a link 

 between Lemnaceae and Araceae (q-v.). 



Pistil, the whole G in syncarpous fl., each cpl. in apocarpous ; -latefl., 

 ? ; -lode, an aborted pistil. 



Piston mechanism. Campanulaceae, Compositae, Leguminosae. 



Pistorinia DC. = Cotyledon Tourn. p.p. (Crass.). 



Pisum (Tourn.) Linn. Leguminosae (ill. 9). 6 Medit. W. As., incl. 

 P. sati-'iaii L. (pea). The fl. mech. resembles Lathyrus. 



Pita, Agave. 



Pitavia Molina. Rutaceae (i). i Chili. 



Pitcairnia L'Herit. Bromeliaceae(3). 1008. Am. Most are terrestrial ; 

 many form stolons at the base. Cult. orn. infl. 



Pitch, Canada, Tsitga canadens-isCatr.; -pine, Pinus pahistris Mill., &c. 



Pitcher-plant, an insectivorous pi. (q.v.} catching insects in pitchers, 

 Cfp/ialotits, Darlingtonia, Heliainphora, Nepenthes, Sarracenia. Cf. 

 also 'Dischidia. 



Pith tree, Aeschynomene aspera L. 



Pithecoctenium Mart, ex DC. Bignoniaceae (i). 20 Brazil to Mex. 



Pithecolobium Mart. Leguminosae (i. i). 120 trop. Stipules often 

 thorny. Fr. often coiled like Medicago. P. Sainan Benth. (trop. 

 S. Am.) is the rain tree, so called because of a legend that it was 

 always raining under its branches. The ejections of juice by the 

 cicadas are responsible for this (cf. Acer, Andira). It shows sleep 

 movement of 1. well. 



Pithecoseris Mart. Compositae (i). i N. Brazil. 



Pithocarpa Lindl. Compositae (4). i W. Austr. 



Pittiera Cogn. Cucurbitaceae (3). 3 C. Am. 



Pittierella Schlechter. Orchidaceae (ll. 18). i Costa Rica. 



Pittoniotis Griseb. = Antirrhoea Comm. (Rubi.) 



Pittosporaceae (EP. , BH.}. Dicotyledons (Archichl. Resales; Poly- 

 galinae BH.}. 10 gen. 90 sp., confined (exc. Pittosporum) to Austr. 

 Trees or shrubs, often climbing, with alt., leathery, evergr., usu. 

 entire, exstip. 1. Resin is present in large quantity in passages at the 

 outer side of the bast. Fls. , reg. , 5-merous; sta. hypog. ; cpls. 2 or 

 more, forming a i-loc. or multi-loc. ovary with parietal or axile plac., 

 and 2-ranked oo anatr. ov. ; style simple. Caps, or berry with album, 

 seeds. Chief genera: Pittosporum, Billardiera, Sollya. The relation- 

 ships are very obscure (see Nat. Pfl. ). 



Pittosporopsis Craib. Icacinaceae. i Burma. 



Pittosporum Banks. Pittosporaceae. 70 trop. and subtrop. \%. The 

 seeds of some are sticky. Some yield useful timber. 



Pituranthos Viv. Umbelliferae (in. 5). 10 Afr., W. As. 



Pituri, Dnboisia Hopiuoodi, F. Muell. (W. Austr.) 



