10 , NORTH AMERICAN FLORA [V01.UME 22 



first not longer than the calyx, at length several times longer and filiform ; calyx- segments 

 ovate, obtuse, shorter than the oblong petals and the obtuse 8-12-seeded carpels. 



Type locality : Texas. 



Distribution : Muddy places, Louisiana to San Luis Potosi, California and Washington. 



4. Tillaeastrum Pringlei Rose, Bull. N. Y. Bot. Gard. 3: 2. 1903. 



Delicate little plants growing in masses in damp mountain soil, 2-3 cm. high. Leaves 

 linear, 3-4 mm. long, acute; flowers axillary, solitary on very short peduncles 1 mm. or 

 less long, in fruit becoming 3 mm. long ; carpels obtuse ; seeds oblong, not papillose- 

 roughened. 



Type locality : Serrania de Ajusco, Federal District, Mexico. 

 Distribution : Known only from the type locality. 



5. Tillaeastrum VaiUantii (Willd.) Britton, Bull. N. Y. 



Bot. Gard. 3: 2. 1903. 



Tillaea VaillaniUWxim, Sp. PL 1 : 720. 1798. 



Bulliarda VaillaniiiXiC. PI. Grasses//. 74. 1801. 



Crassula VaiUantii Schoenl. in B- & P. Nat. Pfl. 32« : 37. 1891. 



Much branched, stems 10 cm. long or less. Flowers peduncled, the peduncles about as 

 long as the leaves ; leaves oblong. 



Type locality : In wet places, France. 



Distribution : Prince Edward Island. Burope and northern Africa. 



Illustrations : DC. PI. Grasses pi. 74 ; Vaillant, Bot. Paris, pi. 10, f. 2 ; Lam. Tabl. Bncycl. 

 pi. 90. 



4. SEMPERVIVUM (Dodoens) I,. Sp. PI. 464. 1753. 



Perennial herbs, the succulent leaves imbricated on the short sterile shoots and scat- 

 tered on the erect flowering stems, with compound cymes of showy flowers. Flowers 6-30- 

 parted. Petals distinct, oblong or lanceolate, acute or acuminate. Stamens twice as many 

 as the petals. Styles filiform ; ovules numerous. Follicles many-seeded. 



Type species, Sempervivum tectorum L. 



1. Sempervivum tectorum ly*. Sp. PI. 464. 1753. 



Flowering stems about 3 dm. high, the barren shoots forming lateral nearly globular 

 tufts. Leaves oval or ovate, the lower 2.5-4 cm. long, thick, short-pointed, bordered by a 

 line of stiff short hairs; cyme large, dense, the flowers sometimes 2.5 cm. broad, pink, 

 sessile along its branches ; petals lanceolate, acute, 2 to 3 times as long as the obtuse ciliate 



sepals. 



Type locality : Europe. 



Distribution : Massachusetts and New Jersey, escaped from cultivation. Native of con- 

 tinental Europe. 



Illustrations : Engl. Bot. pi. 1320 ; Fl. Deutsch. ed. 5, pi. 2653 ; Britt. & Brown, 111. Fl. /. 



1820. . 



5. SEDELLA Britton & Rose, Bull. N. Y. Bot. Gard. 3: 45. 1903. 



Diminutive Californian annuals, with small ovate to ovate-oblong leaves and small 

 yellow cymose flowers. Calyx with 5 very small, triangular acute teeth. Petals 5, linear to 

 ovate-lanceolate, yellow, united at the base, spreading (?). Stamens 10. Carpels oblong, 

 1-seeded, the seed erect. 



Type species, Seduin pumilum. Benth. 



Petals linear. 



Petals ovate-lanceolate. 



1. S. pumila. 



2. S. Con^-doni. 



1. Sedella pumila (Benth.) Britton & Rose, Bull. N. Y. 



Bot. Gard. 3 : 45. 1903. 



Sedum pumilum Benth. Pi. Hartw. 310. 1849. 



Annual, usually branched, 3-8 cm. high, the branches erect or ascending, very slender. 

 Leaves ovate-oblong, thick, 2-5 mm. long, broadest near the base, sessile, subcordate, 

 acutish or obtuse at the apex, alternate, or the lower often opposite; cyme few-forked; 



