308 
Ottoa cenanthoides Ii. B. K. Nov. Gen, et Sp. v, 20 t. 428 (1821), 
Stems rather variable in height, 2 to 4.5 dm. high; leaves fistulose, nodose; rays 
variable in length; flowers white; fruit on pedicels 5 to 8 mm. long, or the central 
one sessile or nearly so, ovate to ovate-oblong, 5 to 6 mm. long; styles long; stylo- 
podia conical; ribs filiform; oil-tubes solitary in the intervals; seed face involute, 
inclosing a small cavity. 
Collected by Mr. EK. W. Nelson on northwest side of the summit of Mount Zempoal- 
tepec, altitude 10,000 to 11,000 feet, June 9, 1894 (No. 643); altitude 8,000 to 10,000 
feet, July 10, 1894 (No, 664); Reyes, altitude 7,500 to 10,000 feet, October 17, 1894 
(No. 1734); summit of Sierra de San Felipe, altitude 10,500 feet, August 20 to 30, 1894 
(No. 1119); also by Mr. ©. G. Pringle, May 22 and August 4, 1894 (No. 4644). 
This hitherto very rare plant has been collected in great abundance by these two 
diligent collectors. Tt has long been a desideratum in American herbaria, and until 
recently sent in by Capt. John Donnell Smith has been unrepresented in the National 
Herbarium. This monotypic genus was first colleeted in the Andes of South Amer- 
ica, and has since been found on the summits of the highest mountains in Mexico 
and Central America. The plant was originally described by Iumboldt, Bonpland 
& Kunth, but apparently without mature fruit. The illustrations of fruit and carpel 
are very unsatisfactory, as they give a very erroneous idea of the seed, ribs, and 
stylopodinm. The genus was originally referred near to (Enanthe, and by Bentham 
& Hooker was placed in the subtribe Scandicinew. Its relationships are much 
nearer Arracacia, from which it scarcely differs, except in its peculiar leaves and 
white flowers. 
Prionosciadium megacarpum Coult. & Rose, sp. nov. 
Stem 2.4 to 4.5 meters high; radical leaves (2 or 3) 9 to 12 dm. long and nearly as 
broad, thrice ternate; leatlets large, 15 to 20 em. long, ovate, acute, crenately toothed 
with a small apiculation, paler and pubescent beneath; upper leaves opposite, twice 
ternate; leaflets lanceolate, acute, cuneate at base, hispidulous above, villous 
beneath; peduncles verticillate; involucel bractlets several, linear, scarious; flowers 
white; fruit large; carpels oblong, 14 to 20 mm. long, obtuse, notched at base, with 
narrow body and broad thin wings; dorsal and intermediate ribs slightly winged; 
oil-tubes 35in the interval, the central one much the larger, 6 on the commissural 
side; seed but slightly flattened dorsally, with narrow sulcus opening into a large 
central cavity, strongly indented beneath the oil-tubes. 
Colleeted by Mr. C. G. Pringle on Sierra de San Felipe, altitude 7,500 feet, June 1 
and October 10, 1894 (No. 4688). 
Here also should be referred Andrieux No, 352, fide Hemsley in lit. 
Prionosciadium linearifolium (Watson) Coult. & Rose; Cicuta linearifolia Wat- 
son, Proc, Amer, Acad. xxii, 415 (1887); 1. watsoni, Watson in part, Proce. Amer. Acad. 
xxv, 150 (18903. ; 
Dr. Watson, in publishing our species of this genus which bears his name, referred 
to it not only Peucedanum mexicanum, which was our type, but also Cicuta linearifolia. 
If the two species are the same, present usage would require the substitution of the 
name linearifolium. <A careful study of our material shows evidence of two fairly 
well-marked species, one of which is found east and the other west of the Sierra 
Madre. 
The eastern species, which is based upon Peucedanum mexicanum Watson, may very 
properly bear the name of Dr. Watson as we had intended, with the following 
synonyiny: Prionosciadium watsoni Coult. & Rose; Watson, Proc, Amer, Acad. xxv, 
150 (1890), in part; Peucedanum mexicanum Watson, Proc. Amer. Acad, xvii, 361 (1882), 
Prionosciadium sp. 
Herb 3 to 5 feet high. Only seeds obtained. Collected by Mr. E. W. Nelson on 
the roul between Tlapa and Tlaliscatilla, Guerrero, altitude 3,900 to 4,500 feet, 
December 5, 1894 (No. 2051) 
