172 
CONTRIBUTIONS TO BOTANY, 
long, 1| line diam. ; the involucels are of a dark brassy metallic 
hue, with a finely granulated surface. 
The Ephedra humilis, Weddell (Ann. Sc. Nat. ser. 3. xiii. 251), 
from Puno in Bolivia, does not appear to be specifically distinct 
from the above plant. The species is much allied to the Ephedra 
dumosa described in a preceding page. 
9. Ephedra Tweediana, Pisch., Meyer, Mem. Acad. Petrop. v. 
99. tab. 9; — ramis ramulisque oppositis, ramosis, erectius- 
culis, teneribus, subvirgatis, pallidis, striatis, subgranulosis, 
imo vaginatis, ad axillas nodosas subarticulatis, internodiis 
subelongatis ; foliis oppositis, aut rarius verticillatim ternis, 
distinctis, imo linea transversali nexis, basi concavis, supeme 
hyalino-membranaceis, acuminatis, et in setam longissimam 
filiformem terminatis : spicellis c? in quaque axilla solitariis, 
vel 2-3-4 glomeratis, sessilibus, oblongis, acutis, basi 4-brac- 
teatis ; involucellis per paria 4-5, imo nexis, decussatim im- 
bricatis, ovalibus, crassiusculis, margine membranaceis, peri- 
gonio subsequilongis ; antheris ssepius 3, interdum 4-5, sessi- 
libus, oblongis, vix exsertis : spicellis fructiferis similibus, 
sed 2-plo majoribus, brevissime pedicellatis •, involucellis ma- 
joribus et paulo crassioribus, pallidis, coriaceis, anguste mar- 
ginatis ; acheniis 2, navicularibus, pallide opacis, oblongis, 
gradatim angustioribus, apice obtuso perforatis, tubUlo ex- 
serto, irregulariter lacerato. — In Provinciis Argentinis, v. v. 
Coro Corto (Prov. Mendosa) et Travesia de Mendosa, d et $ 
(mihi lecta, anno 1826) ; v. s. in herb. Hooker., Travesia de 
Mendosa (sub E. Mendocensis) et in Pampas (sub titulo E. 
australis) (Gillies); Patagones (Carmen, Rio Negro) in Prov. 
Buenos Ayres, det? (Tweedie). 
This species appears to have a wide range over the extent of 
the Pampas, in localities which are more or less saline. It has 
a branching ligneous root, from which numerous slender stem- 
lets ascend, which throw off other occasional branchlets at the 
nodes, forming a shrub 1 or 2 feet in height, with somewhat 
longer branches which run along the ground or trail upon 
others for support. The opposite or verticillately disposed 
branches are slender, subflexuose, of a pale greenish colour, 
I to 1 line diameter, with internodes 1 to If inch apart ; the 
nodes are somewhat swollen, often articulate, and embraced by 
the bases of the leaves, which form opposite cup-shaped cartila- 
ginous projections at each node, joined together by a transverse 
line ; the leaflets are 3 lines long, subulate, suberect, with hya- 
line membranaceous margins, gradually diminishing into a long 
curved setaceous point. The male spikelets generally abound in 
the younger branchlets, where two or three are often crowded 
