344 ONAGRACEAE (EVENING PRIMROSE FAMILY) 



1896. Puberulent or nearly glabrous: leaves low on the stem, usually lyrately- 

 pinnatifid: calyx-tips not free: capsule 10-25 mm. long. Wyoming and Colo- 

 rado and far northwestward. 



15. GAURA L. 



Annual, biennial, or perennial herbs, with alternate narrow leaves, and 

 white, pink, or red flowers in terminal spikes or racemes. Calyx-tube narrow, 

 prolonged beyond the ovary, the limb 4-lobed. Petals clawed, unequal. 

 Stamens usually 8, declined, each with a small scale at the base. Ovary 

 4-celled; united styles declined; stigma 4-lobed, surrounded by a cup-like 

 border; ovules usually 4, pendulous. Fruit nut-like, ribbed or angled, in- 

 dehiscent or nearly so, 1-4-seeded. 



Anthers oval; fruits fusiform, 8-ribbed . . . . . . 1. G. parviflora. 



Anthers linear or nearly so; fruit strongly 4-angled, at least above. 

 Plants tall, erect, herbaceous. 



Fruit sessile 2. G. neo-mexicana. 



Fruit with a slender stipe-like base . . . . . . 3. G. coloradensis. 



Plants low, with assurgent stems from a subligneous base . . 4. G. coccinea. 



1. Gaura parviflora Dougl. Hook. Fl. Bor. Am. 1: 208. 1832. Perennial 

 herbs or shrubby plants with much-branched stems : leaves alternate : flowers 

 yellow, axillary: calyx-tube slender, longer than the ovary: ovary 4-celled, 

 elongated; stigma disk-like, entire: capsules elongated, narrowed at the base, 

 more or less curved; seeds sometimes tuberculate. In dry soil; rather infre- 

 quent; from the Missouri to Oregon. 



2. Gaura neo-mexicana Wooton, Bull. Torr. Bot. Club 25: 307. 1898. 

 Stems virgately branched above: leaves lanceolate, subsessile, entire or sin- 

 uate: pubescence subvillous and viscid glandular above: calyx-segments 

 oblong-spatulate, barely longer than the tube: petals obovate, 1 cm. long, 

 rose-pink: style villous below the middle: fruit obovate-pyramidal, sessile. 

 New Mexico and also reported from Colorado. 



3. Gaura coloradensis Rydb. Bull. Torr. Bot. Club 31: 572. 1904. Her- 

 baceous biennial with fusiform root: stem 5-7 dm. high, finely strigose: leaf- 

 blades narrowly oblanceolate, 5-10 cm. long, callous-denticulate, finely 

 strigose: inflorescence slender and rather lax, 1.5-2 dm. long: calyx-tube about 

 2 cm. long, finely strigose; segments about 1 cm. long, linear-lanceolate, re- 

 flexed: petals about 8 mm. long, spatulate, pink, short-clawed: fruit 8-10 mm. 

 long, fusiform, 4-angled, tapering below into a short and rather slender stipe- 

 like base. Northern Colorado. 



4. Gaura coccinea Pursh, Fl. Am. Sept. 733. 1814. Erect or ascending, 

 much branched, canescent or glabrate, 1.5-4 dm. high: leaves oblong, lanceo- 

 late, or linear-oblong, denticulate, repand, or entire, acute or obtuse at the 

 apex, 1.5-3.5 cm. long: flowers red, turning scarlet: fruit terete below, 4-sided 

 and narrowed above, canescent, 6-8 mm. long. (G. glabra Lehm., a nearly 

 glabrous form; G. parvifolia Torr., glabrate and with numerous small linear 

 leaves; G. marginata Lehm., puberulent, and the leaves and calyx-lobes 

 rather narrower than in the typical species.) Manitoba and Minnesota to 

 Arizona and Texas. 



16. CIRCAEA L. 



Low, slender, perennial herbs, with opposite petioled leaves and small white 

 flowers in racemes. Calyx-tube slightly prolonged beyond the ovary, its 

 limb 2-parted. Petals 2, notched. Stamens 2, alternate with the petals. 

 Ovary 1-2-celled; ovules usually 1 in each cavity. Fruit obovoid, indehis- 

 cent, bristly with hooked hairs. 



Leaves undulate-denticulate; raceme bractless 1. G. pacifica. 



Leaves sharply dentate; bracts present . 2. C. alpina. 



1. Circaea pacifica Ach. & Mag. Bot. Zeit. 29: 392. 1871. Mostly glabrous; 



