206 



CRASSULACEAE. 



Stamens of the same number as the sepals ; minute herbs. 

 Stamens twice as many as the sepals ; succulent herbs. 

 Flowers 4-s-parted. 



Carpels erect ; flowers often polygamous. 

 Carpels spreading ; flowers perfect. 

 Flowers 6-i2-parted. 



VOL. 

 i. Tillaeastruu 



2. Rhodiola. 



3. Sedum. 



4. Sempci 



i. TILLAEASTRUM Britton, Bull. N. Y. Bot. Card. 3: I. 1903. 



Minute, mostly glabrous, aquatic or mud-loving succulent herbs, with opposite 

 leaves and very small solitary axillary flowers. Calyx 3-5-parted. Petals 3-5, distinct, 

 united at the base. Stamens 3-5- Carpels 3-5, distinct. Styles short. Ovules usually 

 Follicles few-seeded or several-seeded. [Latin, from the affinity of these plants with i 

 genus Tillaea.] 



About 20 species, of wide geographic distribution. Besides the following, another occur 

 the western and southern States 



Flowers sessile or short-peduncled. 



Fruiting peduncles as long as the leaves or longer. 



I - I' . 



i. Tillaeastrum aquaticum (L.) Britton. Pigmy-weed. Fig. 2131. 



Tillaea aquatica L. Sp. PL 128. 1753. 



Tillaea simplex Nutt. Journ. Acad. Phil, i : 114. 1817. 



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



Tillaeastrum aquaticum Britton, Bull. N. Y. Bot. Card. 3 : i. i . 



Stems ascending or erect, $'-3' high, glabrous. Lc, 

 linear-oblong, entire, acutish or obtuse at the apex, connat t 

 the base, 2"-$" long, at length shorter than the interne 

 flowers sessile or short-peduncled, I" broad ; calyx-lobes, pe< - 

 stamens and carpels 4, rarely 3, petals greenish, about t\\ < 

 the length of the calyx-lobes; follicles ovoid, longer than ic 

 calyx-lobes, 8-io-seeded. 



Muddy banks of streams, Nova Scotia to Massachusetts 

 Maryland, Louisiana and Texas, near the coast, Washingtoi o 

 Lower California and Colorado. Stem often rooting at the n< . 

 Also in Europe and northern Africa. July-Sept. 



2. Tillaeastrum Vaillantii (Willd.) Britton. Vaillant's Pigmy- 

 weed. Fig. 2132. 



Tillaea Vaillantii Willd. Sp. PI. i : 720. 1798. 



Tillaeastrum Vaillantii Britton, Bull. N. Y. Bot. Card. 3: 2. 1003. 



Similar to the preceding species, 4' long or less, the oblong to linear- 

 oblong leaves about 2" long. Fruiting peduncles elongated, becoming as 

 long as the leaves or longer. 



Prince Edward Island ; Nantucket. Europe and northern Africa. Perhaps 

 a race of the preceding species. 



2. RHODIOLA L. Sp. PI. 1035. 1753. 



Fleshy perennial herbs, with erect, mostly simple stems, broad, rather thin dent 

 entire leaves and dioecious or polygamous, yellow, greenish or purplish flowers in termial 

 cymes. Flowers 4-parted or 5-parted. Calyx shorter than the petals. Carpels distinct, ert. 

 Style very short or none. [Greek, rose, referring to the rose-scented roots.] 



About 8 species, natives of the north temperate zone. Besides the following, 4 others onir 

 in western North America and i on Roan Mountain, North Carolina. Type species: Rh< 

 rosea L. 



