Rydberg : Rocky Mountain flora 55 



broadly oval, short-acuminate, usually mereh" den- 

 tate; the lateral ones often oblique at the base. 4. y. lexanum 

 Fruit not at all or slightly constricted at the base; 

 leaflets lanceolate, ovate or obovate, or the ter- 

 minal one rhombic, long-acuminate, usually more 

 or less lobed. 



Fruit glabrous or with a few scattered hairs, 

 similar to those of the pedicels; mucro of 

 tlie anthers minute or obsolete; leaflets 

 glabrate above in age. 

 Racemes seldom more than i dm. long; wings 

 scarcely at all decurrent on the body of 

 the fruit. 5. N. interius. 



Racemes in fruit 1.5-2 dm. long; wings de- 

 current on the body of the fruit almost to 

 the bottom of the sinus. 6. A^. Kingii. 



Fruit densely puberulent; mucro of the anthers 

 more distinct, nearly I4 mm. long; leaflets 



densely pubescent on both sides. 7. N. californicum. 



Leaflets sharply and evenlj' serrate except towards the base; 



style obsolete. 8. A^. mexicanum. 



I. Negundo orizabense Rydb. sp. nov. 



A tree with glabrous, brownish twigs; leaves 3-foliolate; 

 pedicels slender, glabrous, 5—10 cm. long; leaflets thin, glabrous or 

 with a few scattered hairs on the ribs below, acuminate at both 

 ends, serrate above the middle, with broadly ovate teeth directed 

 forward and mucronate; the terminal leaflet rhombic-oval, 5-10 

 cm. long, with petiolules 1-2 cm. long; the lateral ones lanceolate, 

 oval or oblanceolate, short-petioluled; racemes in fruit 2 dm. long 

 or more, the pedicels very long and slender, the lower 5-8 cm. 

 long; samaras ascending, glabrous; body oblong, about i cm. 

 long and 4 mm. wide, acute but not constricted at the base, with 

 one strong and several weak longitudinal veins; wing about 2 cm. 

 long and nearly i cm. wide, somewhat incurv^ed above, not 

 decurrent on the body. 



Mexico: Orizaba, 1853 and 1855, Fred. Miiller (type, in herb. 

 Columbia University). 



2. Negundo Negundo (L.) Karsten, Deuts. Fl. 596. 1880-3* 

 Distribution: From Ontario and Vermont to Georgia, Mis- 

 souri and Illinois. 



3. Negundo Nuttallii (Nieuwl.) Rydb. 

 Acer fraxinifoliiim Nuttall, Gen. N. Am. i: 253. 1818. Not 

 Negundium fraxinifoliimi Raf. 1808. 



* For other synonyms see Nieuwland, American Midland Naturalist 2: 136. 191 1. 



