30 



Tubes lacerate, fading to grayish-brown or dirty white ; context nearly white ; 

 pileus and stipe dull smoky-brown when dry. .S". holocyaneus (Atk.) Murrill 



7. Stipe black and rooting. 8 

 Stipe neither black nor rooting. 9 



8. Pileus smoky-brown, subtomentose ; margin thin, inflexed ; context white; tubes 



regular, polygonal, entire, 2 mm. long, 0.5 ram. in diameter ; stipe cylindrical, 

 light-brown above, black and rooting below ; spores white, elliptical, 7X5/"- 



S. radicatus (Schw.) Murrill 



Pileus drab-colored, nearly glabrous ; margin thin, inflexed when young ; context 



milk-white even when dry ; tubes white, irregular, toothed, I mm. long, 0.25 



mm. in diameter ; stipe short, sooty-black as far as the decurrent tubes, attached 



to buried wood ; spores white, 3-4 X 5-7/'- ^- subradicatus Murrill 



9. Pileus gray, glabrous or nearly so ; margin very thin ; context rosy-gray, soft, 



fleshy, thin when dry ; tubes small, 0.25-0.5 mm., unequal, decurrent ; stipe 

 short, concolorous. S. griseiis (Peck) Murrill 



Pileus brown. 10 



10. Stipe dark-purple, very thick ; pileus fulvous-brown, purplish at times, clothed 

 with short tomentum, margin very obtuse ; context reddish beneath the cuticle, ' 

 marked when dry with a black concentric line limiting growth ; tubes white, 2 

 to a mm. 5". persicimis (B. & C. ) Murrill 



Stipe yellowi.sh-brown, usually excentric ; plants cespitose ; pileus yellowish- 

 brown, pruinose; margin thin ; context rose-tinted when dry, dark-red next to 

 the tubes, which are small, 1-3 X 0.3 mm., decurrent, rose-colored when dry, 

 the edges fimbriate. S. Whiteae Murrill 



A PALM FROM THE MID-CRETACEOUS* 



By Edward W. Bkrkv 



The enormous number of exi.sting palms, considerably over 

 one thousand species, are about equally divided between the 

 oriental and occidental tropics, with many monotypic genera, 

 showing well the marked effects of geographical distribution and 

 isolation on the formation of species. There are no outlying 

 forms, the highest northern latitude reached being about 43° in 

 Europe, and the highest southern latitude about 45° in New 

 Zealand. 



Lesquereux writing in 1878 t records fossil palms in 52° 

 north latitude in both America and hLurope. Since then remains 

 have been described from as far north as 80° (Grinnell Land, 

 vSpitzbergcn), and two fine species are recorded from the Tertiary 



* Published by permission of the Maryland (Ecological Survey. 

 t lertiary Mora. 



