Part 1, 1905] CRASSULACEAB 9 



2. Tillaea connata R. & P. Fl. Per. 1 : 70. 1798. 



Tillaea rubescens H.B.K. Nov. Gen. & Sp. 6 : 43. 1823. 



Branched, erect or prostrate, 2-9 cm. high. Leaves lanceolate, connate at the base, 

 acute, 1-4 mm. long; flowers several in the axils or sometimes solitary, pedicelled, or 

 sessile ; calyx- segments oblong-lanceolate to ovate-lanceolate, sharply acuminate, 2 mm. 

 long ; petals similar to the cal3^-segments but shorter ; seeds 1 or 2. 



Type locality : On rocks among mosses, Chancay, Peru. 

 Distribution : Lower California ; near City of Mexico ; Bcuador to Peru. 

 Illustration : R. & P. Fl. Per. pi. 106,/. a. 



3. TILLAEASTRUM Britton, Bull. N. Y. Bot. Gard. 3 : 1. 1903. 



Bulliarda DC. Bull. Soc. Philom. 3*9 : 1. 1801. Not Bulliarda Neck. 1790. 



Small or minute, glabrous, annual aquatic or uliginous herbs, with opposite entire leaves 

 and very small axillary solitary flowers. Calyx-segments mostly 4, distinct. Petals usually 

 4, distinct, or united at the base. Carpels usually 4, distinct. Styles short. Ovules few to 

 several. Carpels few-seeded to several-seeded. 



Type species, Tillaea aquatica L. 



Flowers sessile or nearly so, the peduncles little elongating in fruit. 



Leaves linear-oblong, 4-6 mm. long. 1. T. aquaticum. 



Leaves narrowly linear, 8-12 mm. long. 2. T. viride. 



Flowers peduncled, the peduncles at length as long as the leaves or longer. 

 Leaves linear : species of the western United States and Mexico. 



Peduncles as long as the leaves or longer. 3. T. Drummondii. 



Peduncles not longer than the leaves; Mexican species. 4. T. Pringlei. 



Leaves oblong ; species of northeastern North America and Europe. 5. T. Vaillantii. 



1. Tillaeastrum aquaticum (I^.) Britton, Bull. N. Y. 



Bot. Gard. 3:1. 1903. 



Tillaea aquatica L. Sp. PI. 128. 1753. 



Tillaea simplex Nutt. Jour. Acad. Phila. 1 : 114. 1817. 



Tillaea ascendens Eaton, Man. ed. 2. 465. 1818. 



Bulliarda aquatica DC. Prodr. 3 : 382. 1828. 



Tillaea angustifolia Nutt.; T. & G. Fl. N. Am. 1 : 558. 1840. 



Tillaea angustifolia Bolanderi S. Wats. Bot. Calif. 1 : 209. 1876. 



Tillaea Bolanderi Greeue, Fl. Fran. 183. 1891, 



Crassula aquatica Schoenl. in E. & P. Nat. Pfl, S^o; 37. 1891. 



Stems 1-8 cm. high. Leaves linear-oblong, entire, connate at the base, 4-6 mm. long: 

 flowers solitary, axillary, sessile or short-peduncled, 1 mm. broad : cal5rx-lobes, petals, sta- 

 mens and carpels 4, rarely 3 ; petals greenish, about twice the length of the calyx-seg- 

 ments ; follicles ovoid, longer than the cal3rx-lobes, 8-10-seeded. 



Type locality : Inundated places, Europe. 



Distribution : In mud. Nova Scotia to Maryland, Louisiana and Texas, Washington to Lower 

 California and Colorado. Europe to northern Africa. 



Illustrations : Fl. Deutsch. ed. 5, pi. 2635; Britt. & Brown, 111. Fl./. 1809. 



2. Tillaeastrum viride (S. Wats.) Britton, Bull. N. Y. 



Bot. Gard. 3: 1. 1903. 



Tillaea viridis S. Wats. Proc. Am. Acad. 23 : 272. 1888. 



Stems numerous, much branched, spreading, 7 cm. long or less. Leaves narrowly 

 linear, 8-12 mm. long, about 1 mm. wide, acute ; flowers very short-peduncled or sessile, 

 minute ; cal3rx-segments broadly ovate, obtuse, about 1 mm. long ; petals longer than the 

 calyx, obtuse, about as long as the carpels; follicles green, obtuse, 8-seeded, about 1 mm. 

 long ; seeds papillose. 



Type locality : Wet places, base of Sierra Madre, Chihuahua. 

 Distribution : Chihuahua. San Luis Potosi. 



3. Tillaeastrum Drummondii (T. & G.) Britton, Bull. N. Y. 



Bot. Gard. 3: 1. 1903. 



Tillaea Drummondii T. & G. Fl. N. Am. 1 : 558. 1840. 



Stems diffusely branched, decumbent, 2-10 cm. long. Leaves linear to linear-lanceolate, 

 Z-A mm. long, about 1 mm. wide, acute, subconnate ; flowers peduncled, the peduncles at 



