176 OXAGRACE^. (KVENING-PRIMROSE FAMILY.) 



nut-likc, l-cellcd, l-sccdcd. — Perennial aquatics, with simple entire leaves in 

 wiiorls, and niiniite flowers sessile in the axils in suiiinicr. (Name from "nrnos, 

 a hui^r, an<l ovpti, <i tail.) 



1. H. vulgaris, L. Leaves in whorls of 8 or 12, linear, acute. — Tends 

 and springs. New York to Kentucky and northwiud : rare. Stems simple, 1°- 

 2° high. Flowers very inconspicuous. (Eu.) 



Order 39. OJ^AGRACE.E. (E vexing-Primrose Family.) 

 Herbs, with -i-inerous (sometimes 2-3- or 5 - 6-merous) perfect and si/m- 

 vietricul Jlowers ; the tube of the calyx cohering with the 2-4-celled ovary, 

 its lobes valoate in the bud, or obsolete; the petals convolute in the bud, some- 

 times wanting; and the stamens us many or twice as many as the petals or 

 calyx-lobes, inserted on the summit of the calyx-tube. Style single, slen- 

 der : stigma 2 - 4-lobed or capitate. Pollen grains often connected by cob- 

 webby threads. Seeds anatropous, small, without albumen. 



« Pai'ts of the flower in twos. 



1. CIrctea. Petals 2, obcordate or 2-lobed. Stamens 2. Fruit 1 - 2-secdecl, bristly. 



* # Parts of the flowers in fours or more. 

 -- Fruit dry and indehiscent, mostly becoming l-celled, 1-4-seeded. 



2. Gaura. Petals -t Stamens 8 and with the long style turned downwards. 



H- ..- Fruit a many-seeded pod, usually loculicidal. 



3. Epilobium, Stamens 8, Petals 4. Seeds with a large downy tuft at the apex. 



4. CEiiothera. Stumens S and petals 4 on the prolonged caly.x-tulie. Seeds naked. 



5. Jiissirea. Stamens 8-12. Petals 4 -6. Calyx-tube not prolonged beyond the ovary. 



6. Itudwigia. Slamens 4. Petals 4 or more. Calyx-tube not prolonged beyond the ovary. 



1. CIRC^A, Tourn. Enciiantek's Nightshade. 



Calyx-tube slightly prolonged, the end filled by a cup-shaped disk, deciduous; 

 lobes 2, reflcxed. Petals 2, inversely heart-shaped. Stamens 2. Fruit inde- 

 hiscent, small and bur-like, bristly with hooked hairs, 1 -2-cclled : cells 1-secdcd. 

 — Low and inconspicuous perennials, in cool or damp woods, with oj)positc thin 

 leaves on slender petioles, and small whitish flowers in racemes, produced in 

 summer. (Named from Cin-e, the enchantress.) 



1. C. Luteti^na, L. Taller (1°- 2° high); /mrra o?-n/c, slightly toothed ; 

 bracts none; hairs of the roundish 2-rel/pd fruit bristly. — Very common. (Eu.) 



2. C. alpina, L. Low (.3' -8' high), smooth and weak; leaves hexirt -shaped, 

 thin, shining, coarsely toothed; bracts minute; hairs of the obovatc-oblong l-celled 

 fruit soft and slender. — Deep woods . common northward. July. (Eu.) 



2. GAURA, L. Gaura. 



Calyx-tube much prolonged beyond the ovary, deciduous ; the lobes 4 (rarely 

 3), reflcxed. Petals clawed, unequal or turned to the upper side. Stamens 

 mostly 8, often turned down, as is also the long style. A small scale-like ap- 

 pendage before the base of each filament. Stigma 4-lobed, .surrounded by a 

 ring or cup-like border. Fruit hard and nut-like, 3- 4-ribbe<l or angled, inde- 



