282 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



The first species of Talinum described from Mexico was T. lineare, 

 collected by Humboldt and Bonpland in central Mexico and de- 

 scribed by Kunth in 1823. Six years later De Candolle published 

 T. napiforme, also from central Mexico. It was not until 1879 that 

 another species was described, Ilemsley's T. mexicanum. Dr. Sereno 

 Watson described two species from northern Mexico, T. brevicaule 

 and T. coahuilense. The second of these seems not to be a true 

 Talinum, but rather to belong in Talinaria, a genus recently pub- 

 lished by Mr. T. S. Brandegee. Talinum greenmanii was described 

 by Doctor Harshberger in 1897 in the Bulletin of the Torrey Botanical 

 Club, along with notes and illustrations of certain other species. The 

 last species to be published was Mr. Brandegee's T. oligospermum in 

 1906. We have seen material of all these and living plants of most 

 of them. 



Calandrinia tuberosa Benth., described from Ilartweg's collections, 

 was regarded by Bentham as closely related to T. lineare. It is said, 

 however, to have obtuse leaves, and we have nothing that agrees 

 with the description in this particular. 



Judging from the differences exhibited by the specimens at hand it 

 seems probable that when the flora of Mexico is better known several 

 other species must be added to this list. More extended field obser- 

 vations of the plants disposed under T. paniculatum would probably 

 reveal some constant differences among them. 



KF.Y TO THE SrECIES. 



Leaves terete. 



Inflorescence not surpassing the leaves. 



Plants 4 cm. high or usually much higher; leaves not 



narrowed conspicuously toward the base 1 . T. greenmanii. 



Plants 2.5 cm. high or less; leaves on long and very slen- 

 der petioles 2. T. parvulum. 



Inflorescence much surpassing the leaves. 



Plants tall, 20 to 40 cm. high; flowers white, 15 mm. in 



diameter; leaves 8 to 10 cm. long 3. T. palmeri. 



Plants less than 20 cm. high; flowers yellow, pink, or 

 purplish red (except in no. 6). 

 Sepals 7 mm. long or more; flowers proportionately 



torge 4. t. brevicaule. 



Sepals 4 mm. long or less; flowers smaller. 



Plants with poorly developed stems or acaules- 

 cent; peduncles appearing to spring from 

 the root. 

 Flowers few; capsules green, very obtusely 



angled 5. T. napiforme. 



Flowers many; capsules purplish, acutely 



angled 6. T. multiflorum. 



Plants with well developed and branched stems, 

 the peduncles arising along the branches. 



Sepals obtuse; capsule subspherical 7. T. mexicanum. 



Sepals acuminate; capsule larger, oblong in 



section, pointed above ...8. T. gracile. 



