February 28, 1913 9 
KEY TO THE SPECIES 
Corolla conspicuous and showy, extending well beyond the calyx teeth at ma- 
turity 
Stems medium, heads ovate-conical, corolla extending 2.5mm. beyond calyx 
teeth; teoth pubescent; vexillum 12mm. long; legume glabrous: seeds 
light brown T. dichotomum 
Stems very stout; heads semi-globose; corolla extending 4mm. beyond calyx 
teeth; teeth densely plumose; vexillum 14mm. long; legume hairy at 
apex: seeds very light yellow T. amoenum 
Stems slender; heads elliptical; corolla extending 3mm. beyond the calyx 
teeth; teeth villous; l:gume glabrous; seeds brown 
T. californicum 
Corolla not showy, but extending slightly beyond the calyx t: eth at maturity 
Heads sessile or very short peduncled; inflorescence usually 2-headed 
Stems slender and decumbent T. Macrael 
Stems stout and erect T. mercedense 
Stems short and rigid T. catalinae 
Heads with peduncles 2cm. or more long 
Calyx teeth 6mm. long; leaflets silver-gray T. petrophilum 
Calyx teeth 4.5mm. long; leaflets narrow and 
acute at both ends T. Traskae 
Calyx teeth 2mm. long: leaflets oblanceolate = _T. pseudo-albopurpureum 
Corolla inconspicuous, about the length of the calyx teeth 
Calyx tube 2 mm. long; leaf margins entire or 
remotely dentate T. albopurpureum 
Calyx tube very short, 1 mm. long; nerves very 
prominent: leaf margins serrulate T. neolagopus 
Calyx tube short, 1.2mm. long; leaf margins irreg- 
ularly and prominently serrulate-dentate T. Helleri 
Corolla concealed, shorter than the calyx teeth 
Calyx tube 1 mm. long, teeth 7mm. long; vexil- 
lum acute, half the length of the teeth T. columbinum 
Calyx tube 2 mm. long, teeth 9 to 1omm. long; 
vexillum obtuse, half the length of the teeth T. olivaceum 
Calyx tube 2mm. long, rigid; vexillum emargi- 
nate, three-fourths the length of the teeth T. insularum 
TRIFOLIUM DICHOTOMUM H. & A. 
An erect, somewhat spreading plant about a foot high, with 
conspicuous dark purple flowers in ovate-conical heads. The 
leaves are obovate to oblanceolate and covered with white hairs. 
The flower heads are at first turbinate, with the center green 
and undeveloped, the outside and lowermost florets only in 
bloom. As the center increases and develops, the head elon- 
gates ingrowth. The lowest series of florets have started to fade 
