EVENING PRIMROSE FAMILY 1 67 



5. GAYOPHYTUM. 

 Very slender erect annuals, differing from Epilobium chiefly 

 in having seeds naked at apex and a 2-celled capsule. 



Seeds covered with short appressed hairs. 



Flowers minute 1. G. lasiospermum Greene. 



Flowers larger, about Y% in. long 2. G. eriospermum Coville. 



Seeds glabrous, either smooth or minutely rough- 

 ened. 

 Stems much forked above, not very leafy; 

 pedicels elongated; capsule irregularly 

 bulging at intervals. 



Flowers minute 3. G. ramosissimum T. & G. 



Flowers larger, about }& in. long 4. G. diffusum T. & G. 



Stems nearly simple or branched especially 

 toward the base, densely leafy; pedicels 

 short; capsule nearly smooth. 

 Capsule narrowly linear, with suberect seeds. 5. G. caesium T. & G. 

 Capsule broadly oblong, flattened, with very 



oblique seeds 6. G. pumilum Wats. 



The above species may be found in the Yosemite district, 

 but they are difficult to distinguish specifically, largely be- 

 cause of the minuteness of their flowers. They are not here 

 described further than in the above synopsis, which is adapted 

 from a report of the Missouri Botanical Garden. 



6. OENOTHERA. Evening Primrose. 



Erect herbs with alternate leaves and yellow flowers. 

 Calyx-tube prolonged beyond the ovary, its 4 lobes reflexed. 

 Capsule 4-celled, sessile. 



1. O. hookeri T. & G. Evening Primrose. Herbage con- 

 spicuously pubescent. Leaves 

 lanceolate, mostly sessile, acute, 

 toothed (upper often entire), 

 4 to 10 in. long. Calyx-tube 1 

 to 2 in. long. Petals 1 to 1$>& 

 in. long, obcordate, yellow fad- 

 ing to rose. Stigma with 4 

 slender lobes. Capsule about 1 

 in. long, 4-sided. 



The open, dryish meadows 

 of Hetch Hetchy, Yosemite, 

 Wawona, and other low val- 

 leys are rendered brilliant in 

 places by the gorgeous yellow 

 bloom of the Evening Prim- 

 rose. It is a stout biennial 3 

 to 6 ft. high. The flowers ap- 



