DESCRIPTION OF PLANTS COLLECTED UPON THE EXPEDITION. 
RANUNCULACEA. 
CLEMATIS LIGUSTICIFOLIA, Nutt. in Torr. & Gr. Flora, vol. 1, p. 9; Gray's Pl. Fendl., p. 3. 
Pose creek ; August and September. 
PAPAVERACEZ. 
ARGEMONE MUNITA, nova species. Planta glaucissima, erecta, tenera, aculeis albis retrorsis 
horrens, circa 23 pedalis. Folia subamplexicaulia elongato-cordata valde repando-sinuata 
undulata lobis rotundatis. Flores in apicibus 3-4 conferti, breviter divaricateque pedunculati. 
Calyx 3-sepalus caducus setosus, quoque sepalo cornuto, cornu in aculeum validum desinente. 
Corolla 6-petala maxima, 3—4" diametro ; petalis cuneato-obovatis margine denticulatis albis 
recte venosis. Germen lanceolato-cylindricum, aculeis rectis dense obtectum. Capsula adhuc 
ignota. 
Stem branching, about 2] feet high. The whole plant very glaucous and, chiefly on the 
Stems and margins of the leaves, densely covered with strong and slightly retrorse prickles. 
Leaves subelasping, elongate-cordate, with oblong rounded lobes deeply repando-sinuate and 
undulate. Flowers in clusters of 3-4 on short divaricate peduncles. Calyx 3-sepalous, prickly, 
each sepal bearing a horn terminating in a strong prickle. Corolla 3-4” in diameter; petals 
six, white, veined, with slightly denticulate margins. Germ lanceolate-cylindrical, densely 
covered with erect prickles. Capsule unknown. 
The specimens submitted to our examination are incomplete, and not sufficiently advanced to 
determine the shape of the mature capsule and seed. We have compared it with various forms 
of A. Mexicana and with the figure of Lindley’s A. grandiflora in Bot. Reg. T. 1264. In ours 
the texture is more delicate than in A. Mexicana, and the habitus of the leaves and branches 
is less acute than in either, being more rounded and undulating ; the peduncles are shorter, 
stouter, and more divaricate. It grows in large patches at Williamson’s Pass, and was in full 
bloom in August and September. 
CRUCIFERAE. 
PACHYPODIUM INTEGRIFOLIUM, Nutt. in Torr. Æ Gr.'s Flora, vol. 1, p. 96. Edge of Mohave 
desert ; September. | 
STANLEYA INTEGRIFOLIA, Torr. in Capt. Sitgreaves’ Report, T. 1. Posé creek; August. Dr. 
Torrey's S. integrifolia differs from James's plant by pedicels much shorter dati the stipes ; in 
the latter, the pedicels are half as long as the stipes. 
