110 



times a little broader) scj^iiicntv, and small white llowers in naked 

 unequally few-rayed umbels. 



1. A. angustifolium Nutt. 1. c. 644. A span or two high: 

 leaves 1 or 2 inches long, biternately or triternately divided, with 

 linear or nearly filiform segments (rarely linear-oblong) : umbels ses- 

 sile; rays from an inch long to wanting; pedicels half inch long to 

 wanting: fruit with narrow commissure, cordate in outline, ^ line 

 long. (Fig. 119.) — Incl. A latifolhan Nutt. 1. c., which is the 

 coarser-leaved form. Helosciadiuin leptophylliiiu^ var. (?) latifol- 

 iitm Hook. & Arn. Bot. Beechey, 347. 



Hillsides, California, from San Bernardino to Mendocino county; also 

 in Lower California (il//.s.s' F. E. FWi, Orcntt). Fl. April and May. 



2. A. patens. One to two feet high, branching above: 

 leaves (1 or 2 inches long) ternately or biternately divided, with 

 long filiform segments: umbels long-peduncled; rays and pedicels 

 as in the last: fruit with broader commissure, ovate, slightly larger. 

 (Fig. l2{).)—Leptocaulis patens Nutt. in DC. Prodr. iv. 107. 

 ?Z. inermis Nutt. in DC. Mem. Umbel. 39. Apiiim patens Wat- 

 son, Bibl. Index. Polypet. 413 



From Missouri to Louisiana, Texas, and New Mexico ( Trr/(/7( Ml 0(1). 

 Fl. June. 



In Bot. Gazette, xii. 2i)3, we referred this species provisionally to 

 LepiocauUs. From that genus it differs, as was pointed out, in its thinner 

 pericarp, absence of strengthening cells, frequent increase in the number 

 of oil-tubes, and suleate seel-face, all of which important characters asso- 

 ciate it with Apiasfrnm. 



36. MUSENIUM Nutt. in Torr. cS: Gray, Fl. i. 642.— 

 Glabrous or scabrous dwarf resiniferous dry ground perennials, 

 from thick elongated roots, acaulescent or dichotomously branch- 

 ing at base, with pinnately decompound leaves, no involucre, in- 

 volucels of a few narrow bractlets, and yellow or white flowers. 



This genus seems to be British American, extending into the United 

 States alocg the Eocky Mountains. Few specimens have been collected in 

 the United States, and hence herbarium material is very scanty. Prof. 

 Macounhas discovered the first two species abundantly represented on the 

 great plains of N. W. Terr., but M. tenuifolium remains veiy poorly known, 

 mature fruit of it not yet having been collected. 



1. M. divaricatum Nutt. 1. c. Decumbent, glabrous: stem 

 short, dichotomously branching from base: leaves bipinnatifid, 



