MEXICAN AND CENTRAL AMERICAN UMBELLIFER^ I4I 



Hidalgo: near Real del Monte (type locality), Rose 4485, June 



2, 1899. 

 Type in Herb. Gray, drawing in Nat. Herb. 



9. Arracacia dissecta C. & R., sp. nov. 



In dense clumps, 9 to 12 dm. high, scabrous on leaf margins and 

 veins beneath, otherwise glabrous; leaves very large, ternately de- 

 compound; segments linear to linear-oblong, 2 to 4 cm. long, entire 

 or occasionally somewhat toothed or cleft, terminating in a conspicu- 

 ous callous apex; uppermost leaves alternate or opposite, much re- 

 duced, sometimes nearly simple; peduncles axillary or terminal, 5 to 

 8 cm. long; rays about 12, unequal, 2 to 8 cm. long; involucre and 

 involucels wanting, or occasionally represented by a bract ; fruiting 

 pedicels 3 to 4 mm. long; fruit (immature) oblong, 4 mm. long, 

 glabrous. 



Pueblo: Acatlan, Rose & Hough 4709, June 27, 1S99. 



10. Arracacia donnellsmithii C. & R. Bot. Gaz. 15 : 261.//. 75. 1890. 

 Guatemala : Todos Santos, altitude 3000 meters. Nelson 3630, De- 

 cember 26, 1S95. Type in Nat. Herb. 



11. Arracacia dugesii C. & R., sp. nov. Plate VIH. 

 Tall coarse herbs, probably 1.2 to 2.5 dm. high, in habit and foli- 

 age suggesting the genus Prionosciaduifti; leaves several times 

 ternate; ultimate segments linear, 5 cm. or less long, acute, entire or 

 with a few irregular sharp teeth; involucre wanting; involucel of 

 several setaceous bractlets ; rays numerous, mostly fruiting, in some 

 umbels often less than 2.5 cm. long and equal, in others more unequal, 

 sometimes 7.5 cm. long ; pedicels 3 to 6 mm. long ; fruit ovate, 6 mm. 

 long ; ribs sharp ; oil-tubes 2 or 3 in the intervals, 4 on the commis- 

 sural side. 



Guanajuato: near City of Guanajuato, Diiges 317, in 1893; same 

 station, Duges^ in 1895; same station, Rose & Hough 4847, 

 July II, 1899. 



12. Arracacia glaucescens Benth. PI. Hartw. 187. 1845. 



The type comes from South America, but it has been reported from 

 Mexico. 



13. Arracacia hemsleyana C. & R., sp. nov. Plate IX. 

 Stems slender, glabrous ; leaves thrice ternate ; leaflets lanceolate, 



long acuminate, 5 cm. or less long, cuneate or truncate at base, sharply 

 serrate, glabrous; inflorescence more or less branching; terminal 

 umbel sessile or short peduncled ; rays 6 to 9, slightly unequal, 1.8 to 

 3 cm. long, somewhat spreading; umbellets several-flowered but only 

 3 or 4 fruiting; involucre and involucels none, or the latter of a few 

 small bractlets; pedicels 4 to 6 mm. long; fruit 6 to 8 mm. long, 

 oblong; stylopodium conical ; flowers purple. 



San Luis Potosi : on limestone ledges, Las Canoas and Tamasopo 

 Canyon, Pringle 5016, June 13-August 21, 1891. 



