1921] natural sciences of philadelphia. 463 



1. Gratioleae. 



Leaves entire to serrate. Seeds brown or yellow. 



Corolla with the ridges to the antero-lateral sinuses low and 

 not projecting beyond those points (so anterior fila- 

 ments simple). Posterior lobes of the corolla httle 

 shorter than the anterior. Seeds reticulate or lon- 

 gitudinally striate. Pedicels frequently bibracteolate. 

 Anther-sacs proximate, no connective arms developed. 

 Seeds reticulate. Leaves not cordate clasping at base. 

 Pedicels bibracteolate (or in Gratiola the bractlets 

 sometimes several, one or wanting). Leaves 

 pinnately veined (except in Hydrotrida), Styles 

 united throughout. Sepals five, acute or obtuse. 

 Pedicels bracted at base (remote from the calyx). 

 Corolla yellow or white, pubescent within at base 

 of posterior lobes. Stamens four. Sepals unequal, 

 and leaves serrate. Plants erect or ascending. 



1. Mecardonia. 

 Pedicels bracted at apex (just beneath calyx). 

 Fertile filaments two, the anterior being rudim- 

 entary or wanting. Corolla yellow or white, 

 its tube much longer than the lobes. Outer- 

 most sepal never more than twice width of 

 innermost. Plants erect. 

 Corolla-tube broad, within densely pubescent 

 on the posterior side. Sepals of nearly uniform 

 length. Plants relatively lax or succulent, 

 the leaves and sepals plane. 



2. Gratiola. 

 Corolla-tube very narrow, within uniformly short- 

 pubescent on all sides. Sepals very unequal 

 in length. Plant stiff, the leaves and sepals 

 re volute. 3. Sophronanthe. 



Filaments four, all with anthers. Corolla blue 

 or white, its tube little longer than the lobes. 

 Outermost sepal over twice width of inner- 

 most. Plants repent. 

 Corolla pubescent within over bases of all lobes, 

 blue throughout; posterior lobes united to 

 apex. A circle of bristles surrounding the 

 base of the ovary. Outer sepal shghtly 

 cor date, evidently exceeding the linear- 

 a ttenuate innermost. Capsuje less than one 

 half as broad as long. Pedicels spreading 

 in fruit. Leaves clasping, broadest proxi- 

 mally, crenate, with five to seven longitudinal 

 nerves. Stem pubescent. Plant lemon-scent- 

 ed. 4. Hydrotrida. 



