312 ANACARDIACEAE (sUMAC FAMILY) 



4-celled, with 2 styles. Fruit 4-lobeid, flattened,^ and emarginate. Flowers 

 mostly solitary, sometimes a stamen and a pistil in the same axil^ 



1. CALLITRICHE L. 



Characters given vmder the family. 



Bracts present; emersed leaves obovate 1. ,C. palustris. 



Bracts wanting; all leaves linear 2. C. bifida, 



1. CalUtriche palustris L. Sp. PI. 969. 1753. Aquatic or growing in the 

 mud, with elongated stems, and floating, rosulate, obovate often emarginate 

 leaves; the submerged ones Unear or nearly so: bracts often Exceeding the 

 fruit: styles erect or spreading; deciduous: fruit orbicular or obcordate, of 

 connate carpels, more or less winged. C. verna. — Across the continent. 



2. CalUtriche bifida (L.) Morong, Mem. Torr. Club 5: 215. 1894. En- 

 tirely submerged: leaves linear or linear-lanceolate, clasping at the base: 

 flowers without bracts: styles reflexed, deciduous: fruit round, deeply notched, 

 sessile, broadly winged on the margins. C. avtumnaLis. — Across the conti- 

 nent in the northern part of our range. 



66. LBINANTHACEAE Lindl. False Mermaid Family 



Glabrous annual herbs, with pungent juice, dissected alternate leaves with- 

 out stipules, and pale, regular, symmetrical flowers. Sepals yalvate, persistent, 

 and accrescent. Petals withering-persistent. Stamens twice as many as the 

 petals, those opposite the petals having a gland at the base outside. 



1. FLOERKIA Wind. 



Flowers solitary at the ends of bractless axillary peduncles, 3-5-merous. 

 Carpels 1-ovuled, distinct, the 5-lobed style rising from the center, in fruit 

 becoming semi-drupaceous, rugose-tuberculate nutlets. 



1. Floerkia occidentalis Rydb. Mem. N. Y. Bot. Gard. 1: 268. 1900. Very 

 slender, less than 1 dm. high, glabrous: leaves pinnate, with 1-2 pairs of 

 oblong leaflets; sepals ovate, acute: petals oblanceolate, about half as long 

 as the sepals: carpels two, sharply rugose-tuberculate. — In wet places; west- 

 em Wyoming, Utah and northwestward. , 



67. ANACARDIACEAE Lindl. Sumac Family 



Shrubs or trees with acrid, resinous, or milky sap, alternate leaves without 

 stipules, and small, regular, commonly polygamous or dioecious flowers. Calyx 

 3-7-cleft. Petals the same number, imbricated in the bud. Stamens as many 

 or twice as many, inserted at the base of the disk. The free ovary 1-celled 

 and 1-ovuled but the styles often 3. Fruit generally a small drupe. 



1. RHUS L. Sttmac 



Leaves trifoliolate or pinnately compound. Sepals and petals usually 5. 

 Stamens inserted imder the edge of a disk lining the' calyx. 



Leaflets 11-31 . . . , , 1. R. cismontana. 



Leaflets 3. 



Large, rhombic ovate 2. R. Rydbergii. 



Small, crenately lobed . , 3. R. trilobata. 



