i 9 2o] SHERFF— BIDENS 105 



Bidens torta, sp. nov. — Fruticosa, glabra, caule non crasso 

 ±5 dm. alta. Folia tripartita, membranacea, serrata, ciliata, 

 tenerrime petiolata, petiolis adjectis<7~i6 cm. longa et 2.5-10 cm. 

 lata, foliolis acuminatis, terminali multo maiore, oblongo-lanceolato, 

 lateralibus sessilibus aut breviter petiolulatis, ovato-lanceolatis, 

 petiolis 1-4 cm. longis. Capitula numerosa, laxe paniculata, 

 mediocria, ligulata, ad anthesin circ. 5 mm. alta et 1.7 mm. lata. 

 Involucri bracteae exteriores circ. 5, tenuiter lineares, glanduloso- 

 pubescentes, 1.5-2.5 mm. longae, interioribus paulo breviores. 

 Ligulae circ. 5, oblongo-oblanceolatae, flavae, ad apicem plus 

 minusve dentulatae, circ. 7 mm. longae. Achaenia tenuiter 

 linearia, nigra, rnaxime torta, glabra, corpore 9-13 mm. longa 

 ad apicem calva aut obscure 1-2-aristata aristis glabris brevissimis 

 (o .1-0.3 mm - longis) . 



Specimens examined. — C. N. Forbes 2092 O, Kawailoa, Oahu, March 2-5, 

 1915 (Herb. Bishop Mus., type; Herb. Field Mus., no. 485294). 



The leaves of this species appear to have rather large leaflets in proportion 

 to the thickness of the petiole. The terminal leaflet becomes 1 dm. long and 

 4 . 4 cm. wide. The branches of the inflorescence are slender and widely 

 diverging. The leaves and inflorescence combine to give a striking superficial 

 resemblance to certain Central American specimens of B. squarrosa H. B. K. 

 The achenes surpass those of nearly all other species in the amount of twisting. 

 The twisting commences early, in the young achene, and the mature achenes 

 are frequently twisted through four or five complete revolutions. 



Bidens gracilis Nutt, Trans. Amer. Phil. Soc. Ser. II. 7:368. 

 1841; Campylotheca gracilis Walp., Rept. Bot. Syst. 2:618. 1843. — 

 No described species of Bidens has been left heretofore in greater 

 obscurity than B. gracilis. From the time of Nuttall's original 

 description, no botanist appears to have given it serious attention. 

 In 1843 Walper categorically transferred the species, along with 

 two others described by Nuttall, to Campylotheca. In 1862 

 Gray (Proc. Amer. Acad. 5:128) referred it, along with Bidens 

 mutica Nutt., to B. sandvicensis Less. Nuttall's types of B. 

 gracilis and B. mutica are still extant in a state of excellent preserva- 

 tion (Herb. Brit. Mus.). The type of B. gracilis is clearly distinct 

 from that of B. mutica. It is distinct also from the specimens that 

 I assume to be of the type collection of B. sandvicensis Less, by 

 Chamisso from Oahu (for example, distrib. Acad. Petropol. in Hb. 

 Kew, ex Hb. Hookeri). In 1888 Hillebrand doubtfully referred 



