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cent, or with stem I-2 in. long; leaves terete, 1-3 in. long, acute, 
green, clustered at top of short stem; inflorescence cymose not 
exceeding the leaves, branched with 5-8 flowers; sepals 2; petals 
5; bright yellow; stamens 7-8, filaments long; ovary round; style 
short; stigma three-grooved; fruit rounded, triquetrous; seeds, 
small, smooth. (Plate 299, fig. 4). 
Volcanic gravel, Sierra de Ajusco, Mexico. 8500 feet. . Possibly 
it is 7. humile described by E. L.Greene. Distributed in Pringle’s 
Plantae Mexicanae as no. 6472. Named in honor of Mr. Jesse 
Moore Greenman, of the Gray Herbarium, Cambridge, Mass. 
Talinum teretifolium belongs to that group of the genus with 
round leaves, as distinguished from those species which have leaves 
more or less flattened, as 7: patens, lineare and brevifolium.* Talinum 
teretifolium is interesting not only on account of its geographical 
distribution, but also from its significance from an histological and 
ecological standpoint. The stem is tuberiform, provided with 
closely appressed scale-leaves (induviae). During the active grow- 
ing season, the perennating stem becomes more or less elongated, 
from which the green succulent stem arises bearing the terete 
foliage leaves. In the fall, just before the cessation of growth, 
rounded, tuberiform branches appear, which finally break from 
the main perennating stem as the plant withers. These small — 
tuberous branches remain dormant during the cold of winter, their _ 
contents being protected by a thick corky layer until spring opens, 
when they give rise to new foliage shoots. One of these tuberi- — 
form branches, or stems, was planted in a pot January 21, 1896, 4 
and watered carefully to determine whether these branches propa- — 
gated the plant non-sexually. On March 25, 1896, a green out- — 
growth appeared. By the end of March the green sprout had 
reached the height of an inch and had eight well-formed terete 
Jeaves. (See Plate 299, fig. 2). It is probable, also, that these — 
ball-like branches aid in the distribution of the plant, rolling from 
place to place. 
Ffistology. The root is long, and in cross section is surrounded 
with cork from six to eight layers thick. As the long, elastic — 
roots are exposed frequently to the drying action of winds, this — 
cork envelope becomes all the more necessary. Internal to the © 
*1893. Thomas Howell, A Rearrangement of American Portulacaceae. Erythea, 3 
pias a 
