WOOTON AND STANDLEY FLOEA OF NEW MEXICO. 459 



Order 37. MYRTALES. 



KEY TO THE FAMILIES. 



Styles wanting; aquatics 101. GUNNERACEAE (p. 473). 



Styles present; land plants. 



Hypanthium merely inclosing the ovary 99. LYTHE.ACEAE (p. 459). 



Hypanthium adnate to the ovary 100. EPILOBIACEAE (p. 459). 



99. LYTHRACEAE. Loosestrife Family. 



1. LYTHRUM L. Loosestrife. 



Herbs with simple sessile entire leaves and slender angled stems; flowers perfect, 

 dimorphous, mostly solitary in the axils; hypanthium short, tubular or narrowly 

 funnelform, about 5 mm. long; petals 4 to 6, rose purple; stamens 8 to 12; ovary 2-celled, 

 superior, becoming 1-celled by the breaking down, of the septum; seeds several. 



1. Lythrum linearifolium (A. Gray) Small, Fl. Southeast. TJ. S. 828. 1903. 



Lythrum alatum linearifolium A. Gray, Bost. Joum. Nat. Hist. 6: 188. 1850. 



Type locality: "Rocks in the Cibolo River," Texas. 



Range; Texas to Arizona, south into Mexico. 



New Mexico: Black Range; Dog Spring; Organ Mountains; Mogollon Mountains- 

 Fresnal; Roswell. Wet ground, in the Upper. Sonoran and Transition zones. 



100. EPILOBIACEAE. Evening primrose Family. 



Annual or perennial herbs, rarely somewhat shrubby; leaves simple, alternate or 

 opposite, exstipulate; flowers 2 or 4-merous, mostly conspicuous, small in two or three 

 genera, axillary, spicate, or racemose, regular or slightly irregular; hypanthium mostly 

 tubular and more or less elongated, sometimes spreading; sepals 2 or 4; petals of the 

 same number; stamens as many as the .sepals or twice as many; pistil usually of 4 

 carpels, with one style and 1 to 4 more or less united stigmas; fruit a 4-valved capsule, 

 sometimes indehiscent and nutlike. 



key to the genera. 



Flowers 2-merous; fruit indehiscent, obovoid, bristly 



with black hairs 1. Circaea (p. 460). 



Flowers 4-merous; fruit various. 



Fruit indehiscent, nutlike 2. Gaura (p. 461). 



Fruit a dehiscent capsule. 



Seeds with a tuft of silky hairs. 



Flowers bright deep red 5. Zauschneria (p. 464). 



Flowers purple to white, never bright red. 



Hypanthium not prolonged beyond the 



ovary; flowers about 2 cm. in 



diameter 3. Chamaenerion (p. 463). 



Hypanthium prolonged beyond the 

 ovary; flowers less than 1 cm. in 



diameter 4. Epilobium (p. 463). 



Seeds without a tuft of silky hairs. 



Hypanthium not prolonged beyond the 



ovary; flowers minute 6. Gayophytum (p. 464). 



Hypanthium prolonged beyond the ovary; 

 flowers much larger. 

 Stigmas discoid or capitate. 



Stigmas capitate; annuals 7. Sphaerostigma (p. 465). 



