274 



PAPILIONACEAE. 



[VOL. II. 



2. Melilotus officinalis (L,.) L,am. Yellow Melilot. Yellow Sweet-clover. 



(Fig. 2069.) 



Trifolium Melilotus officinalis 1,. Sp. PI. 765. 1753. 

 Melilolus officinalis Lam. Fl. Fr. a: 594. 1778. 



Resembling the preceding species, but the flow- 

 ers are yellow. Standard about equalling the 

 wings and keel; leaflets oblong, oblanceolate, or 

 oval, serrate, the apex rounded, not truncate; pod 

 about 2" 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 naturalized 

 from Europe. Native also of Asia. Summer, 

 blooming later than M. alba, where the two grow to- 

 gether in southern New York. Old English names, 

 Balsam-flowers, Hart's-clover, King's-clover, King's 

 Crown, Heart wort. 



Melilotus Indica (I,. ) All., introduced on ballast 

 about the seaports, and an exceedingly abundant 

 weed in the Far West, may be readily distinguished 

 from this by its much smaller yellow flowers. 



Ononis ripens I,., 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. Sp. PI. 764. 1753. 



Herbs, with (in our species) mostly 3-foliolate, denticulate leaves, and purple pink red 

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

 teeth nearly equal. Petals commonly persistent, their claws more or less completely adnate 

 to the stamen-tube. Stamens diadelphous, or the tenth one separate for only a portion of its 

 length. Ovary sessile or stipitate, few-ovuled. Pod oblong or terete, often included in the 

 calyx, membranous, indehiscent or tardily dehiscent by i suture, i-6-seeded. [Latin, refer- 

 ring to the 3 leaflets.] 



About 250 species, most abundant in the north temperate zone, a few in South America and 

 South Africa. Besides the following, about 50 others occur in the western part of the continent. 



Flowers yellow. 



Head 6"~9" long; stipules linear; leaflets all sessile. i. T. agrarium. 



Head 4"-6" long, nearly globose; stipules ovate; terminal leaflet stalked. 



Head 20-40- flowered; standard conspicuously striate. 2. T. procumbens. 



Head io-i2-flowered; standard scarcely striate. 3. T. 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-lobes. 

 Corolla whitish, shorter than the calyx-lobes. 

 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. T. pralense. 



Heads always distinctly peduncled. 

 Calyx-teeth pubescent. 

 Plant glabrous throughout. 

 Flowers pedicelled ; heads umbel-like, globose. 



Heads i' in diameter or more; peduncles i'~3' long. 

 Prostrate; pubescent; perennial. 

 Ascending; pubescent; annual or biennial. 

 Stoloniferous; glabrous; perennial. 

 Heads 6"-o" in diameter; lower peduncles 2' -8' long. 



Ascending or procumbent; flowers pink, pinkish, or purple. 



Ascending; calyx much shorter than the pink or nearly white corolla. 



12. T. hybridum. 

 Procumbent; tufted; calyx nearly equalling the purple corolla. 



13. T. Carolinianum. 

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



4. T. incarnaltim. 



5. T. arvense. 



7. T. medium. 



8. T. Beckwithii. 



9. T. Virginicum. 



10. T. reflexum. 



11. 71 stoloniferum. 



