10 PROCEEDINGS OP THE ACADEMY OF 



Cyperus Heermannii, n. s. Culmis erectis 2 3-pedalibus, trigonis ; 

 umbella 11 13 radiata ; radiis insequalibus 2-interioribus sessilibus ; longi- 

 oribus subsequalibus 7 8-policaribus ; involucro 9 13 phyllo ; phyllis in- 

 sequalibus, longioribus 9 12-policaribus ; radiis 15 17-stachyis, basi confertis 

 apice divergentibus 15 25-floris ; squamis ovatis acutis lateralibus rufescen- 

 tibas margine albescentibus ; carinis viridiscentibus ; involucelli phyllis 

 numerosis linearibus, vel setaceis ; longioribus 1 2-policaribus ; achenio ob- 

 tuso ellipsoideo et obtuso trigono stylo profunde trifido. 



California. Dr. Heermann. 



Spikelets densely aggregated in nearly tbe same plane, with numerous 

 linear or setaceous leaves interspersed. Often tbe beads of spikes are proli- 

 ferous, with a ray about an inch in length, crowned with spikelets. 



Chsetocyperus (Elseocharis) membranaceus, n. s. Culmis filiformibus 

 erectis, crespitosis, 2 3-policaribus planis ; spica oblongo-ovata 4 12-squa- 

 mata, acuta imbricata ; squamis ovatis, acutis vel subobtusi lateralibus dense 

 albo-hyalinis dorsis stramineis ; achenio lato-ovoideo nigro, subacute triangu- 

 lari et abrupte in tuberculum angustum erosum rostrato ; setis nullis. 



Llano County. Grows in small tufts. 



Spikes greyish white 3 4 lines long, achenia quite as broad as long, dull 

 black, not shining. A few of the scales are tinged on the back with brownish 

 red, but most of the backs are straw colored and not keeled ; the back of the 

 lower scale is green. 



Eleocharis cylindrica, n. s. Culmis planiusculis filiformibus 9 12-poli- 

 caribus ; spica cylindrica subacuta 4 7 lin. longa ; squamis ovatis vel ovato- 

 lanceolatis acutis inferioribus obtusis rufescentibus ; margine albo-hyalinis 

 carinis stramineis ; achenio parvo ovoideo obtuse triangulari glabro tuberculo 

 magno subconico apiculato ; setis 3 6 caducis nucula brevioribus. 



Northern Texas. June. 



Spikes 1 2 lines in diameter. Stems below immersed in water. Nuts 

 pale yellow, small ; tubercle large in proportion, contracted at the base and 

 shortly apiculated. 



Eleocharis microformis, n. s. Culmis setaceis csespitosis erectis 1 2- 

 policaribus, planiusculis ; spicis ovatis obtusis vel subacutis 10 12-squa- 

 matis ; squamis ovatis acutis vel subobtusis, rufescentibus ; carinis virides- 

 centibus ; achenio glabro nitido lato obovato pyriformi ; setis (i nuculam 

 sequantibus ; tuberculo lato applanato breve apiculato. 



Northern Texas. June. 



Mature achenia black and shining, crowned with a broad white tubercle, 

 with a short point in the centre. Scales reddish brown, with green keels. 



Eleocharis acutisquamata, n. s. Culmis striato-sulcatis erectis filifor- 

 mibus 10 15-policaribus ; spica oblongo-ovata acuta 15 40-squamata ; squa- 

 mis ovato-lanceolatis, acutis rufescentibus apice membranaceis ; achenio obo- 

 vato pyriformi et minute reticulato ; tuberculo breve conico apiculato ; setis 

 nullis ; spica 4 lin. longa. 



San Saba County. May and June. 



Rhizoma large and creeping ; achenia pale yellow, biconvex tubercles brown. 



On the Uniformity of Relative Characters between Allied Species of European 



and American Trees. 



BY THOMAS MEEHAN. 



To whatever principles the origin of species may be owing, the following 

 observations tend to show that their respective differences are the result of 

 one unvarying law. 



Noticing that European willows, oaks and other trees retained their green 



[Jan. 



