COMMELINACEAE. 



VOL. I. 



6. Tradescantia montana Shuttlw. Moun- 

 tain Spiderwort. Fig. 1159. 



Tradescantia montana Shuttlw. ; Britt. & Br. 111. Fl. I : 



377- 1896. 



Green and glabrous or somewhat pubescent, 

 stems slender, simple or sparingly branched, 

 i-2 tall. Leaves lanceolate or linear-lanceo- 

 late, 4'-io' long, 2"-6" wide, mostly distant, their 

 sheaths enlarged ; bracts similar to the leaves but 

 shorter ; umbels mostly solitary and terminal, ses- 

 sile in the bracts, rather densely flowered ; pedi- 

 cels and calyx glabrous or pubescent ; flowers 

 less than i' broad; sepals lanceolate, acute, about 

 3" long. 



In woods and thickets, mountains of southwestern 

 Virginia to Kentucky and Georgia. June-Aug. 



7. Tradescantia pilosa Lehm. Zigzag Spider- 

 wort. Fig. 1160. 



T. pilosa J. G. C. Lehm. Sem. Hort. Hamb. 16. 1827. 

 Tradescantia flexuosa Raf. Atl. Journ. 150. 1832. 



More or less puberulent or short-pilose, stem stout, 

 l-3 high, commonly flexuous, often branched. 

 Leaves broadly lanceolate, acuminate at the apex, 

 mostly narrowed at the base, 6'-is' .long, $'-2' wide, 

 dark green above, paler beneath ; bracts usually 

 narrower and shorter than the leaves ; umbels 3-8, 

 terminal and axillary or on short axillary branches, 

 densely many-flowered ; pedicels and calyx pubescent 

 and more or less glandular, rarely nearly glabrous ; 

 corolla lilac-blue, g"-is" broad. 



Southern Pennsylvania to Illinois and Missouri, 

 south to Florida. June-Aug. 



Family 19. PONTEDERIACEAE Dumort. Anal. Fam. 59. 1829. 

 PICKEREL-WEED FAMILY. 



Perennial aquatic or bog plants, the leaves petioled, with thick blades, or 

 long and grass-like. Flowers perfect, more or less irregular, solitary or spiked, 

 subtended by leaf-like spathes. Perianth free from the ovary, corolla-like, 6-parted. 

 Stamens 3 or 6, inserted on the tube or the base of the perianth ; filaments filiform, 

 dilated at the base or thickened at the middle ; anthers 2-celled, linear-oblong or 

 rarely ovate. Ovary 3-celled with axile placentae, or i-celled with 3 parietal 

 placentae ; style filiform or columnar ; stigma terminal, entire or minutely toothed ; 

 ovules anatropous, numerous, sometimes only I of them perfecting. Fruit a 

 many-seeded capsule, or a i -celled, i -seeded utricle. Endosperm of the seed 

 copious ; embryo central, cylindric. 



About 5 genera and 25 species, inhabiting fresh water in the warm and temperate regions of 

 America, Asia and Africa. 



Flowers 2-lipped, stamens 6 ; fruit a i-seeded utricle. i. Pontederia. 



Flowers regular; stamens 3 ; fruit a many-seeded capsule. 2. Heteranthcra. 



i. PONTEDERIA L. Sp. PI. 288. 1753. 



Leaves thick with many parallel veins, the petioles long, sheathing, arising from a hori- 

 zontal rootstock. Stem erect, i -leaved, with several sheathing bract-like leaves at the base. 

 Flowers blue, ephemeral, numerous, spiked, the spike (or spadix) peduncled and subtended 

 by a thin bract-like spathe. Perianth 2-lipped, the upper lip of 3 ovate lobes, the middle 

 lobe longest, the lower lip of 3 linear-oblong spreading lobes. Stamens 6, borne at unequal 

 distances upon the perianth-tube, 3 of them opposite the lower lip, the others opposite the 

 upper lip; anthers oblong, subversatile, introrse. Ovary 3-celled, 2 of the cells abortive and 

 empty. Fruit a i-seeded utricle, enclosed in the thickened tuberculate-ribbed base of the 

 perianth. [In honor of Giulio Pontedera, 1688-1757, professor of botany in Padua.] 



Seven or eight species, natives of America. The following is the type of the genus. 



