560 ONAGRACEAE 



Locs. — Stockton, Sanford; Los Banos, M. S. Jussel; Visalia (Contrib. U. S. Nat. Herb. 

 4:102). 



Rcfs. — ROTALA RAMOSIOR Koehnc ; Mart. Fl. Bras. 13*:194 (1875); Jcpson, Man. 665 

 (1925). Avimamiia ramosior L. Sp. PI. 120 (1753), type loc. Virginia, Clayton. Ammannia 

 humilis Michx, Fl. Bor. Am. 1:99 (1803), type loc. North Carolina; Jepson, Fl. W. Mid. Cal. 

 325 (1901), ed. 2, 272 (1911). 



ONAGRACEAE. Evening Primrose Family 



Herbs. Leaves simple, entire, toothed, lobed or divided. Flowers mainly 

 showy, borne in spikes or racemes, or solitary. Ovary completely inferior, the 

 calyx commonly prolonged beyond it into a calyx-tube (or hypanthium-tube). 

 Sepals, petals and stamens borne on the summit of the calyx-tube, or rarely on 

 the summit of the ovary when the calyx-tube is absent. Calyx-lobes 4 (sometimes 

 5 or 2) . Petals 4 (sometimes 5 or 2) , the stamens as many or twice as many. Pol- 

 len commonly cobwebby. Ovary 4 (sometimes 5 or 2) -celled; style 1; stigma 

 capitate or discoid, or 4-lobed. Fruit a capsule, rarely bur-like or indehiscent. 

 Seeds mostly small, naked or with a tuft of hairs (coma) at apex; endosperm 

 none. — Genera about 26, species about 480, all continents. 



Bibliog.— Spach, Eduardo, Onagrarieae (Hist. Nat. Veg. 4:335-416, — 1835). Rothrock, 

 J. T., Synopsis of N, Am. Gaurineae (Proc. Am. Acad. 6:347-354, — 1864). Broekens, D. J., 

 tJber den Stammbaum der Onagraceae (Recueil des travaux botaniques Neerlandais 21:383-515, 

 — 1924). Johansen, D. A., Proposed phylogeny of the Onagraceae based primarily on number 

 of chromosomes (Proc. Nat. Acad. Sci. 15:882-885, — 1929) ; The hypostase and seed sterility in 

 Onagraceae (Madrono 1:165-167, — 1928) ; New chromosome numbers in Onagraceae (Am. Jour. 

 Bot. 16:595-597, — 1929). Munz, P. A., and Hitchcock, C. L., A study of the genus Clarkia, 

 with special reference to its relationship to Godetia (Bull. Torr. Club 56:181-197, — 1929). 



A. Calyx-limb divided down to the ovary and persistent on the fruit after flowering ; parts of the 

 flowers in 4s or 5s; fruit a capsule (indehiscent in no. 1). 



Petals 5, 6 to 7 lines long; fruit at length reflexed 1. Jussieua. 



Petals none or minute; fruit erect 2. Ludwiqia. 



B. Calyx-limb deciduous after flowering. 

 Parts of the flowers in 4s. 



Fruit a capsule, dehiscent. 



Ovary 4-celled; calyx-tube produced above the ovary. 

 Seeds with a tuft of hairs at one end. 



Flowers large ; corolla and calyx scarlet 3. Zauschneria. 



Flowers small; corolla white, red or purplish 4. Epilobium. 



Seeds naked. 



Anthers innate (attached at or near the base) ; flowers purple, rose-color or 

 white, never yellow. 



Calyx-lobes erect or ascending; petals small or minute 5. Boisdutalia. 



Calyx-lobes reflexed or the tips remaining united and turned to one side in 

 anthesis. 

 Petals distinctly clawed, often much lobed; stamens 8 or 4.. 6. Clarkia, 

 Petals sessile, not lobed (except in one species) ; stamens 8.-7. Godetia. 



Anthers versatile (attached near the middle) ; flowers yellor or white 



8. Oenothera. 



Ovary 2-celled ; calyx -limb divided down to the ovary ; flowers white 9. Gayophytum. 



Fruit indehiscent 10. Gaura. 



Parts of the flowers in 2s; fruit bur-like 11. Circaea. 



1. JUSSIEUA L. 



Glabrous perennial herbs, ours aquatic or of muddy shores. Leaves alternate. 

 Flowers yellow, solitary in the axils, pediceled. Calyx divided down to the sum- 

 mit of the ovary, its lobes 5. Petals 5. Stamens twice as many. Fruit (in ours) 

 5-celled. Seeds very numerous. — Species 36, tropical regions, all continents save 

 Europe. (Bernard de Jussieu, who founded the natural system of classification.) 



1. J. calif ornica Jepson. Yellow Water- weed. Stems 1 to 10 feet long; 

 leaf-blades oblong to obovate, % to 2 inches long, the floating ones elliptic or 



