536 



Pontederacca Pontederia. 



1. P. cordata (fig. 259). Pickerel-weed. A common North 

 American plant, 1 to 2 feet high, desirable for the hardy 

 aquarium. P. angustifolia is a variety 

 with narrow lanceolate leaves cordate 

 at the base, and also smaller bright 

 blue flowers. 



These plants should be placed in 2 or 3 

 feet of water, or they will not bear our 

 winters. 



ORDER XV.-COMMELYNACE.ffi. 



Herbs with linear or lanceolate flat 

 usually sheathing leaves and solitary 

 spicate or umbellate flowers. Perianth- 

 segments 6, the outer 3 herbaceous, inner 

 petaloid. Stamens 6 or fewer. Fruit a 

 2- or 3-celled few-seeded dehiscent cap- 

 sule. There are about 20 genera and 

 250 species, with the exception of those 

 enumerated below, nearly all tropical. 



1. TRADESCANTIA. 



Herbaceous tufted or creeping plants. 

 Stem branched, fleshy, 1 to 2 feet high. 

 Leaves entire, linear-lanceolate,sheathing, 

 glabrous. Flowers in terminal sessile or 



stalked umbels. Perianth 6-parted, the 3 exterior sepaloid, 

 and the 3 interior petaloid. Filaments bearded. An Ame- 

 rican genus, named in remembrance of Tradescant, gardener to 

 Charles I. 



1. T. Virginica. Spiderwort. A very pretty and interesting 

 plant growing about a foot and a half high, with linear-lan- 

 ceolate acuminate glabrous ciliate sheathing leaves and sessile 

 bracteate umbels. Outer perianth-segments green, inner rosy- 

 purple. Filaments densely bearded with long spreading jointed 

 purple hairs. There are several varieties, including one with 

 white petals and purple filaments, another with beautiful rose- 

 coloured petals, and also a double-flowered variety. 



2. T. rosea. A similar though smaller and less hardy plant, 



Fig. 251). Pontederia cordata. 

 (J nat. size.) 



