\ 



capsule about 4 mm. in diameter, loculicidal. Nesaea salicifolia H.B.K. 



Along resacas, streams or in wet soil in brushlands in the Rio Grande Plains and 

 Valley of s. Tex., Mar.-June; from Tex., s. through Mex. to C.A. and S.A.; also 

 Jam. 



2. Heimia longipes (Gray) Cory. Fig. 540. 



Subshrubby to somewhat herbaceous plants with sprawling and trailing much- 

 branched slender stems to 9 dm. or more long, glabrous throughout; leaves sub- 

 sessile, linear, acute at apex, auriculate at base, with prominently revolute margins, 

 to 5 cm. long and 4 mm. wide; peduncles filiform, elongated, often about as long 

 as the leaves, bibracteolate below the flowers; calyx 5-7 mm. long, with short 

 2-grooved triangular lobes; petals pink to purple, obovate, 6-7 mm. long; style fili- 

 form, much-exserted; capsule about 4 mm. in diameter, opening by a little lid and 

 then splitting septifragally. Nesaea longipes Gray. 



On seepage rocks and about springs in the Edwards Plateau and the Trans-Pecos 

 of Tex., May-July; apparently endemic. 



3. Lythnim L. Loosestrife 



Herbs or shrubs with 4-angled stems; leaves opposite, alternate or sometimes 

 whorled, entire; flowers usually solitary in the axils, often dimorphous, with a 

 short bibracteolate peduncle; calyx tube cylindric, 8- to 12-ribbed, 4- to 7-toothed, 

 with an equal number of appendages in the sinuses; petals 4 to 6, attached to the 

 rim of the calyx tube, rarely wanting; stamens 4 to 12, inserted rather low on the 

 calyx tube; style filiform; capsules cylindrical, included in the calyx tube, mem- 

 branous, 2-celled, usually bursting irregularly; seeds numerous. 



About 35 species of wide geographical distribution. 



Lythrum lineare L., a plant with mostly opposite linear-oblong leaves which is 

 found in and about brackish and saline marshes east to Florida and New Jersey 

 has been reported from Texas. We have seen no material of it from our region. 



1, Stem leaves mostly widest at or above the middle, tapering or abruptly con- 

 tracted into a subpetiolar base (2) 



1. Stem leaves mostly widest below the middle, somewhat rounded to subauricu- 



late at the usually sessile to clasping base (3) 



2(1). Stem leaves broadly elliptic to elliptic-obovate, rounded to subobtuse at 

 apex; endemic in Texas Edwards Plateau 1. L. ovalifolium. 



2. Stem leaves typically narrowly elliptic, acute to acuminate at apex; wide- 



spread in eastern third of Texas and Oklahoma.. ..2. L. lanceolatum. 



3(1). Leaves of inflorescence typically linear-lanceolate; appendages of calyx 

 tube subulate and erect, much longer than the teeth; distribution 



Panhandle and north-central Texas and Oklahoma 



3. L. dacotanum. 



3. Leaves of inflorescence typically linear; appendages of calyx tube fleshy- 



mammillate and curved outward, about as long as the teeth; dis- 

 tribution south-central and west Texas westward 



4. L. calif ornicum. 



1. Lythrum ovalifolium Koehne. Fig. 541. 



Perennial herb to 35 cm. high, the stem much-branched from near base; stem 

 leaves broadly elliptic to elliptic-obovate, rounded to obtuse at apex, to 25 mm. 

 long and 8 mm. wide, abruptly contracted at base, membranous; leaves of inflores- 

 cence similar to stem leaves but much smaller; calyx tube 5-6 mm. long; petals 

 obovate, lavender, 3-4.5 mm. long, 1.5-2 mm. wide. 



Rare along and in water of rivers and streams in the e. Edwards Plateau of cen. 

 Tex., Apr. -June; endemic. 



1158 



