Family 7. LIMNANTHACEAE 



By Per Axee Rydberg 



Annual, glabrous herbs with pungent juice, growing in wet places, with 

 alternate pinnately dissected leaves, no stipules, and solitary axillary bractless 

 flowers. Flowers regular, perfect and complete. Hypanthium shallow, saucer- 

 shaped, thickened. Sepals 3-5, valvate or slightly imbricate, persistent. 

 Petals 3-5, marcescent. Stamens 6-10, more or less perigynous ; those opposite 

 to the sepals with a gland outside the base ; anthers rounded, introrse. Gy- 

 noecium 2-5-carpellary ; ovaries distinct, 1-ovuled, opposite the sepals ; 

 styles united to near the top, basal, rising in the center between the ovaries ; 

 stigmas simple. Carpels becoming semi-drupaceous, tuberculate nutlets ; 

 seeds erect, anatropous, without endosperm ; embryo straight ; radicle 

 inferior. 



Flowers 4-5-merous ; petals convolute in aestivation, truncate or emarginate, 

 equaling or exceeding the sepals ; peduncles straight. 1. Limnanthes. 



Flowers 3-merous; petals open in aestivation, obtuse or acute, half as long as 

 the sepals ; peduncles recurved. 2. Floerkea. 



1. LIMNANTHES R. Br. Phil. Mag. III. 2 : 70. 1833. 



Low annuals, profusely branched at the base. Leaves usually more or less doubly 

 piunatifid. Flowers usually conspicuous on axillary, straight peduncles. Sepals 4-6, val- 

 vate, ascending even in fruit. Petals 4 or 5, white, yellow, or rose, convolute in aesti- 

 vation. Stamens 10 ; filaments distinct, those opposite the petals usually shorter. Ovaries 

 4 or 5 ; style 4 or 5-cleft at the apex ; stigmas minute. 



Type species, Limnanthes Douglasii R. Br. 



Sepals ovate, copiously white-villous ; leaves more or less pubescent with long 

 hairs ; petals white, slightly if at all emarginate. 

 Petals longer than the sepals ; stem mostly erect, 1-3 dm. high. 1. L. alba. 



Petals not exceeding the sepals ; stem decumbent, 3-7 cm. high. 2. L.floccosa. 



Sepals lanceolate, glabrous or with a few scattered hairs ; leaves glabrous. 

 Flowers 5-merous ; petals 6-18 mm. long. 



Petals much exceeding the sepals, emarginate or truncate at the apex. 



Petals pale-rose or whitish with short longitudinal purplish lines. 3. L. rosea. 



Petals yellowish with white tips, or the latter rarely lilac in age. 



Leaves twice piunatifid. with narrowly linear divisions ; tubercles of 



the carpels with prominent ridges. 4. L. Douglasii. 



Leaves once pinnatifid, the divisions entire or toothed with oblong or 

 lanceolate lobes or teeth. 

 Petals 12-18 mm. long, emarginate; carpels densely tubercled. 

 Primary divisions of the leaves usually pinnately 3-9-toothed or 

 cleft with lanceolate divisions ; tips of the petals white ; 

 sepals glabrous. 5. L. sulphurea. 



Primary divisions of the leaves entire, oblong or linear, or 

 cleft with similar divisions ; petals in age tipped with lilac ; 

 sepals usually slightly hairy. 6. L. versicolor. 



Petals usually less than 1 cm. "long, truncate or slightly refuse; 

 carpels smooth or slightly tuberculate at the apex. 7. L. gracilis. 



Petals scarcely exceeding the sepals, rounded at the apex. 8. L. pumila. 



Flowers 4-merous ; petals 3-4 mm. long. 9. L. Macounii. 



1. Limnanthes alba Hartw.; Benth. PI. Hartw. 301. 1848. 



Floerkea alba Greene, Fl. Fran. 100. 1891. 



Annual ; stems copiously branched at the base, erect or ascending, 1-3 dm. high, 

 glabrous; leaves 3-10 cm. long, sparingly long-villous, once to twice pinnately dissected, 

 with oblong or lanceolate divisions ; peduncles 2-10 cm. long ; sepals ovate, acuminate, 6- 



Volume 25, Part 2, 1910] 97 



