PA PIL ION A CEA . 5 39 



Flowers white ; standard a little longer than the wings. i. M. alba. 



Flowers yellow ; standard about equalling the wings. 2. M. officinalis. 



1. Melilotus alba Desv. WHITE MELILOT. WHITE SWEET-CLOVER. (I. F. 

 f. 2068.) Erect or ascending, 1-3 m. high. Leaves rather distant; leaflets ob- 

 long or slightly oblanceolate, serrate, narrowed at the base, truncate, emarginate 

 or rounded at the apex, 1-2 cm. long; stipules subulate ; racemes slender, 5-10 cm. 

 iong, often I -sided; pedicels 2 mm. long or less; pod ovoid, slightly reticulated, 

 glabrous, 2-3.5 cm - ^ on g- ^ n was te places, frequent throughout our area and in the 

 Southern States. Adventivc or nat. from Europe. Leaves fragrant in drying, as 

 in other species of the genus. June-Nov. 



2. Melilotus officinalis (L.) Lam. YELLOW MELILOT. YELLOW SWEET- 

 CLOVER. (I. F. f. 2069.) Resembling the preceding species. Leaflets ob- 

 long, oblanceolate or oval, serrate, the apex rounded, not truncate; pod about 4 

 mm. long, with irregularly reticulated veins, often slightly pubescent with appressed 

 hairs. In waste places, frequent throughout our area and in the Southern States. 

 Adventive or nat. from Europe. Summer, blooming later than M. alba. 



Melilotus Indica (L.) All., introduced on ballast about the seaports, and an exceed- 

 ingly abundant weed in the Far West, may be readily distinguished from this by its much 

 smaller yellow flowers. 



Ononis rfepens L., an herb of the tribe TRIFOLIEAE, with axillary flowers, forming 

 terminal leafy racemes, has been found as a waif in central New York. The genus is 

 distinguished from others of the tribe by its monadelphous stamens. 



12. TRIFOLIUM L. 



Herbs, with mostly 3-foliolate (occasionally 4- ii-f< Violate) denticulate leaves, 

 the flowers in dense heads or spikes. Stipules adnate to the petiole. Calyx-teeth 

 nearly equal. Petals commonly persistent, their claws adnate to the stamen-tube. 

 Stamens diadelphous, or the tenth one separate for only a portion of its length. 

 Ovary few-ovuled. Pod often included in the calyx, membranous, indehiscent or 

 tardily dehiscent by I suture, i-6-seeded. [Latin, referring to the 3 leaflets.] 

 About 250 species, most abundant in the north temperate zone. Besides the fol- 

 lowing, about 50 others occur in the southern and western states. 



Flowers yellow. 



Head 12-18 mm. long ; stipules linear ; leaflets all sessile. i. T. anreum. 

 Head 8-12 mm. long, nearly globose; stipules ovate; terminal leaflet stalked. 



Head 2O-4o-flowered ; standard conspicuously striate. 2. 7". procumbens. 

 Head 3~2o-flowered ; standard scarcely striate. 3. 7". dubium. 



Flowers red, purple, pink or white. 



Head or spike much longer than thick ; calyx silky, its teeth plumose. 



Corolla crimson, equalling or exceeding the calyx-teeth. 4. T. incarnatum. 

 Corolla whitish, shorter than the calyx-teeth. 5. T. arvense. 



Head globose, oval or ovoid ; calyx nearly glabrous. 



Flowers sessile, or very nearly so ; heads dense, ovoid, oval or globose. 

 Heads sessile, or nearly so. 6. 7'. pratense. 



Heads always distinctly peduncled. 



Calyx-teeth pubescent. 7. T. medium. 



Plant glabrous throughout. 8. T. Beckwithii. 



Flowers pedicelled ; heads umbel-like, globose. 



Heads 2.5 cm. in diameter or more; peduncles 2-8 cm. long. 



Prostrate ; pubescent ; perennial. 9. 7'. Virginicum. 



Ascending ; pubescent; annual or biennial. 10. 7". reflexitm. 



Stonoliferous ; glabrous ; perennial. n. 7'. stoloniferum. 



Heads 12-18 mm. in diameter ; lower peduncles 5-20 cm. long. 

 Ascending or procumbent : flowers pink, pinkish or purple. 



Ascending ; calyx much shorter than the pink or nearly white co- 

 rolla. 12. T. hvbridtim. 

 Procumbent ; tufted ; calyx nearly equalling the purple corolla. 



13. T. Carolinianum. 

 Creeping ; flowers white or pinkish. 14. T. repens. 



i. Trifolium aureum Poll. YELLOW OR HOP-CLOVER. (I. F. f. 2070.) Gla- 

 brous or slightly pubescent, annual, 1.5-5 dm. high. Leaves petioled; stipules 

 acuminate, 7-15 mm. long, adnate to the petiole for about one-half their length; 

 leaflets all from the same point, obovate or oblong, finely denticulate, narrowed at 



