220 ONAGRACE.E. 



M. piunatum Walt. Leaves in whorls of 3's and 5's, sometimes 

 pcattered, the floral linear, pectinate toothed, or cut serrate, the teeth 

 comparatively few, 5-12 lines long, gradually changing into the sub- 

 merged which are in crowded verticels, the capillary pinnae sparse; 

 spikes 3-6 inches long : petals purplish, somewhat persistent, stamens 4, 

 very rarely 6 : mature fruit about L line long : carpels strongly 2-keeled. 



Order XXXVIII. ONAGRACEvE. Dumort. Anal. Fam.xxxvi. 35. 



Herbaceous or sometimes shrubby plants with entire or 

 toothed leaves, with flowers in the axils or in terminal spikes 

 or racemes. Sepals united into a tubular calyx, the limb 4- 

 parted rarely more or less ; valvate in the bud. Petals usually 

 as many as the lobes of the calyx, and attenuate with them, 

 inserted on the summit of the tube twisted in the bud, some- 

 times wanting. Stamens as many or twice as many as the lobes 

 of the calyx, rarely half as many, inserted with the petals, fila- 

 ments distinct; ovary coherent with the tube of the calyx. 2-4- 

 (ox by abortion) 1-2-celled ; placenta in the axis, style elon- 

 gated or filiform; stigma capitate or 4-lobed, fruit capsular 

 with mostly loculicidal dehiscence, or dry and indehiscent, 

 rarely baccate. Seeds indefinite or solitary in each cell, ana- 

 tropous without albumen ; embryo straight. 



Tribe I. Jussie^e. Limb of the calyx divided quite down 

 to the ovary and persistent on a many-seeded capsule. Seeds 

 naked. 



1. Ludwigia. Petals 4 or none. Stamens 4. Capsules short. 



Tribe II. Onagre^e. Limb of the free tube of the calyx, 

 when there is any, deciduous from the ovary or capsule. Cap- 

 sule loculicidal, few to many seevled. Parts of the flowers in 

 fours. 



* Seeds comose at the apex; stamens 8, lower leaves often opposite. 



2. Epilobium. Calyx 4-parted nearly down to the ovary or with a 

 short and campanulate tube beyond it. 



* * Seeds not comose : leaves all alternate. 



+- Anthers attached near the middle and versatile. Petals gen- 

 erally yellow or white. 



3. Gayophytnm. Calyx-tube not produced beyond the ovary ; this and 

 the membranous capsule only 2-celled. 



++ Stamens all of equal length. 



= Stigma deeply 4-cleft, its segments linear. 



4. Onagra. Ovules and seeds horizontal, inserted in 2 or rarely in sev- 

 eral rows, prismatic-angled. 



5. (Euothera. Ovules and seeds ascending in one row ; not angled : 

 flower- buds erect: flowers yellow. 



6. Auogra. Ovules and seeds ascending, not angled, in two rows: 

 flower-buds drooping, flowers pink or white. 



