686 WATER PLANTS 



growth, frequent branching, much veg. repr. They have no rigid 

 anatomy, and are marked by absence of cuticle, stomata, &c., and 

 by presence of enormous intercellular spaces. The 1. shows 4 types, 

 (i) the floating 1. of Hydrocharis, Nymphaeaceae, Ranuncidus, Trapa, 

 &c., a round 1. with cuticle and stomata above; (2) the awl-shaped 

 type of submerged 1. of Isoetes, Lobelia, Sitbularia, &c., plants which 

 can often survive upon land ; (3) the ribbon type of most Monocots., 

 e.g. Valtisneria, Potamogeton, Ruppia, Zostera ; (4) the much divided 

 type with linear segments, Bidens, Ceratophyllum, Myriophyllum, 

 Podostemaceae, Ranunculus, Trapa, &c. Heterophylly is common, 

 cf. Cabomba, Callitriche, Potamogeton, Ranunculus, Sagittaria, Sal- 

 vinia, Trapa, &c. 



Many hibernate by buds formed at the ends of branches, full of 

 reserves, e.g. Hydrocharis, Myriophyllum, Potamogeton sp., Utrtcu- 

 larja, by tubers, Potamogeton, sp., Sagittaria, by rhizomes, Potamo- 

 geton, sp., Nymphaeaceae. Cf. Lemnaceae. 



Most are perennials ; annuals in Marsilea, Naias, Subzdaria. 

 Fls. usu. wind- or insect-pollinated, but Ruppia, Zostera, &c. are fert. 

 under water. The seeds usu. sink, and often show interesting features 

 in germination. A few amphibious pi. exist, which can also live on 

 land, e.g. Liltorella, Polygonum. In the trop. occur the interesting 

 fams. Hydrostachvaceae, Podostemaceae, and Tristichaceae (y.v.}, in 

 swift water. 



Cf. also Aldrovanda, Alisniaceae, Aponogeton, Araceae, Azolla, 

 Butomaceae, Eichhornia, Elatinaceae, Elodea, Hippuris, Hydrocleys, 

 fussieua, Lemna, Limnantkemum, Limnobium, Nelumbium, Nipa, 

 Nuphar, Nymphaea, Peplis, Pistia, Pontederiaceae, Potamogetonaceae, 

 Rumex, Samolus,Sesbania, Stratiotes, Victoria, Zannicliellia, &c. , and 

 see Schenk, Die Wassergewcichse, and Schimper's and Warm ing's Plant 

 Geography. 



Watsonamra O. Ktze., Standley (Pentagvni.a'BeTith.). Rubiaceae (i. 7). 

 9 Mexico, C. Am. 



Watsonia Mill. Iridaceae (in). 12 Afr., Maclag. Cult. orn. fl. 



Wattle, Acacia. 



Wax, Ceroxylon, Copernicia, Myrica, Palmae, Rhus ; - flower, Angrae- 

 cum, Hoya; -gourd, Benincasa; Japan-, Rhns vernicifera DC.; 

 -myrtle, Myrica; -palm, Copernicia cerifera Mart.; -tree, Rhus; 

 waxy leaf, Agave, Crambe, Dischidia, Elymits, &c. 



Wayfaring 1 tree, Viburnum. 



Weather plant, Abnts precatorius L.; -thistle, Carlina. 



Webbia DC. =Vernonia Schreb. p.p. (Comp.). 



Webera Schreb. ( Tarenna Gaertn.). Rubi. (i. 8). 30 trop. As., Afr. 



Wetoerbauera Gilg et Muschler (Braya p.p.). Crucif. (4). i Peru, Arg. 



Weberbauerella Ulbrich. Leguminosae (in. 7). i Peru. 



WeberocereusBrittonetRose(GVrap.p.). Cact. (ill. i). 2C.Am.,W.I. 



Websteria S. H. Wright (Ditlichium Prs.). Cyperaceae (i). i Florida. 



Weddellina Tul. Tristichaceae. i Guiana, N. Brazil., IV. squanut- 

 losa Tul. Roots flattened, with haptera, shoots borne at their 

 edges. Two kinds, veg. to 2^ feet long and much branched, and 

 short unbranched flowering ones. Between the branches of the long 

 shoots are branches of limited growth, as in Tristicha. 



