3S West American Scieiiiist. 



Our western plants differ from the Eastern type of Echinocystis 

 only in their more turgid seeds, hypogseous cotyledous and per- 

 ennial tuberous roots. In the seeds there is displayed every var- 

 iation between the obovate and orbicular, and from nearly globose 

 to very much flattened. Eminent botanists who have given special 

 attention to the Cucurbitace^e agree in the opinion that our Paci- 

 fic Coast plants in question form hardly a well characterized sec- 

 tion of Echinocystis. In the natural orders most nearly allied, 

 Cactacese and Loasaceae for example, much wider differences in 

 the character of seeds are allowed in a genus. To take the case 

 of Mentzelia, the diversity of the seeds, all the way from nearly 

 shapeless to thin flat and winged on the one hand, and to almost 

 exactly cubical on the other, is manifold greater than what we 

 shall have in Echinocystis as here allowed; and as for the nature 

 of the root^ whether tuberous or fibrous, perennial or annual, in 

 what orders does one ever take such characters into considera- 

 tion for a moment, when trying to determine the limits of a 

 genus ? The species of this western group are now become quite 

 respectably numerous, and arrange themselves somewhat natur- 

 ally as follows. 



E FABACEA, Naudin, Ann. Sci. Nat. 4 ser. xii and xvi: Me- 

 garrhiza Californica, Torr. Pac. R. Rep. vi, fide S. Watson, 

 Bot. Cal. i. 241. 



E. MACROCARPA, Greene, Bull. Cal. Acad. i. 188. 



E. GiLENSis, Greene, 1. c. 189. 



E. Oregana, Cogniaux, Diag. Cucurb. Nouv. ii. 87 and 97. 



E. Mara. Mara muricata, Kellogg, Proc. Cal. Acad. i. 38: 

 Megarrhiza Mara, Watson, 1. c. 



E. GuADALUPENsis. Greene, 1. c. 223; 



Megarhiza Guadalupensis. Watson, 1. c. 242. 



The seeds of this are hardly '*sub-globose," they are, on the 

 contrary, more compressed than in any other one of the western 

 species. They are round-ovoid, more than an inch long, nearly 

 an inch broad and less than a half inch in thickness. This plant 

 is abundant on the island of Santa Cruz, and is distinguishable 

 from E. macrocarpa, which grows there along with it, by the 

 seeds chiefly; and the difference between them, both as to the 

 number of the seeds, and their size and form, is very clear. 



E. muricata, Kellogg. 1. c. 57; Megarrhiza muricata, Watson, 

 1. c. 



Although this is one of the oldest species it remains one of the 

 rarest. I met with it myself, for the first time, during the past 

 season on the tops of the mountains, back of Vacaville. The 

 whole plant is beautifully glaucous, the fruit of the size of a small 

 lemon and of the same yellow color. The soft spines are rather 

 numerous, in my specimens, and the seeds four, whereas accord- 

 ing to the description they are two only. It is barely possible we 

 are including two species under this name. Prof. E. L. Greene. 



