1915] Fernald & St. John,— Species and Varieties of Bidens 23 
Island plant common upon Prince Edward Island and characterized 
by having upwardly barbellate awns. The latter was then proposed 
as Bidens tripartita, var. heterodoxa Fernald.! 
Subsequent collections and a more detailed study of the plants of 
Prince Edward Island and the Magdalens show that, although strongly 
simulating Bidens tripartita in foliage and in the flat usually 2-awned 
achene, the plant of these islands differs from that characteristic 
European species in having much smaller and copiously pubescent 
achenes and in having the outer foliaceous bracts of the involucre 
glabrous or at most very remotely ciliate toward the base. In B. 
tripartita, on the other hand, the much larger achenes are strictly 
glabrous and the outer involucral bracts conspicuously ciliate to the 
tip. The plant from the Gulf of St. Lawrence in its outer involucral 
bracts closely resembles the more southern, normally 4-awned B. 
connata Muhl., and occasional specimens with three or four awns tend 
to strengthen this similarity. In B. connata, however, the midribs 
of the two faces of the achene become strongly thickened at summit, 
thus giving to the top of the achene an obviously 4-angled appearance; 
and the surfaces of the achene are ordinarily quite glabrous or at most 
remotely setulose. In the plant of the Magdalen Islands and Prince 
Edward Island the copiously pubescent achenes are quite as flat as in 
B. tripartita and B. comosa (Gray) Wiegand. For this reason we feel 
justified in considering the insular plant a distinct species which is 
related on the one hand to B. tripartita (which is definitely known in 
North America only from the Gaspé Peninsula), on the other to the 
common continental species, B. connata. 
B. heterodoxa (Fernald), n. comb. B. tripartita L., var. heterodoxa 
Fernald, Ruopora, xv. 76 (1913). Caule tenui glabro 1.5-9 dm. alto; 
foliis simplicibus vel 3-5-partitis utrinque glabris, imis tenuiter petiola- 
tis, lamina vel loba terminali lanceolata vel anguste ovata 2.5-12 em. 
longa argute grosseque serrata; capitulis discoideis vel radiatis; 
involueri bracteis foliaceis 3-6 lineari-lanceolatis elongatis, basi 
glabris vel sparse ciliatis, bracteis interioribus oblongis obtusis strami- 
neis atro-striatis 7-9 mm. longis; paleis linearibus 4-striatis; achaeniis 
planis strigosis 2-4-aristatis margine aristisque sursum barbellatis, 
marginalibus cuneatis 4.5 mm. longis 1.8 mm. latis cum aristis 1.5 mm. 
longis coronatis, interioribus 6-7 mm. longis vix 2 mm. latis aristas 
2-3 mm. longas gerentibus. 
The stem slender, glabrous 1.5-9 dm. high: leaves simple or 3—5- 
parted, glabrous on both surfaces; the lower slender-petioled; blade 
1 RHODORA, xv. 76 (1913). 
ge M us ; 
