Book  (1909)  Page(s) 211, Vol. 2.  
 
R. pisocarpa Gray. Cluster Rose.
Slender, 3 to 5 feet high; prickles few, slender and straight, or none; leaves green and glabrous [smooth] above, paler and often puberulent [covered with fine down] beneath, not glandular, leaflets finely serrate; stipules strongly and often abrupty dilated upwards...; flowers in corymbs or solitary; ...hips globose.
Rich hill slopes and vally or cañon flats, 50 to 3000 feet: Lake, Humboldt and Trinity County to Shasta, Siskiyou and Del Norte Counties, North to British Columbia.
June - August.

Book  (1900)  Page(s) 351.  
 
Rosa pisocarpa. (Botanical Magazine t.6857.) Hardy. A species with reddish glabrous stems armed with straight prickles. Leaf rather small, with five leaflets. Flowers 2-3 together, bright pink, about 1 in. in diam. Fruit globose, reddish, 1/3-1/2 in. in diam. North California.

Article (magazine)  (1897)  Page(s) 152-153.  
 
R. pisocarpa A. Gr.

a. Feuille. — Poils simples sur les deux épidermes, surtout sur l'inférieur. Poils glandulifères nuls. Épiderme supérieur reclicurviligne, d'une épaisseur de 19-23 μ, à cellules petites. Épiderme inférieur d'une épaisseur de 10-16 μ, à cellules moyennes ou petites, rarement grandes. Stomates d'une longueur de 25-26 μ, plus petits que les cellules environnantes ou au plus égaux à elles. Mésophylle bifacial, d'une épaisseur de 62-73 μ, composé de 5-6 assises, les 2-3 supérieures transformées en palissades remplissant 1/2-3/4 de l'épaisseur totale. Parenchyme spongieux peu ou pas lacuneux. Faisceaux libéro-ligneux des nervures et du pétiolule ordinairement sans fibres péridesmiques. Péliole renfermant à sa base 3-5 fais- ceaux disposés en arc.

b. Tige. — Cuticule épaisse. Parenchyme cortical composé de 14 15 assises de cellules étroites et allongées tangentiellement. Bois très vasculaires, vaisseaux étroits. Moelle à cellules moyennes ou petites.

Article (magazine)  (1896)  Page(s) 14-15.  
 
Rosa pisocarpa A. Gray In its habitual form, such as Asa Gray described and figured in the Botanical Magazine (pl. 6857), R. pisocarpa cannot be confounded with any other species. Its prickles regularly paired, and its leaflets more or less conspicuously rounded at base, distinguish it from R. blanda. Its slender and straight prickles, and its inflorescence with small and usually numerous flowers, separate it from R. Nutkana. Lastly, the form of its prickles, which are straight and not curved or hooked at the tip, permits no confusion with R. Californica.
Despite these differences, there is more or less confusion....

Magazine  (1886)  Page(s) tab 6857.  Includes photo(s).
 
ROSA pisocarpa.
Native of British Columbia and Oregon.
Nat. Ord. Rosaceae. — Tribe Roseae.
Genus Rosa, Linn. ; (Benth. et Hook.f. Gen. Pl. vol. i. p. 625.)
Rosa pisocarpa ; gracilis, fere glaber, inermis v. aculeis stipularibus paucis parvis rectis v. ascendentibus, foliolis parvis ellipticis obtusis serratis, floribus parvis solitariis corymbisve paucifloris, bracteis paucis linearibus, calycis tubo urceolato glabro, lobis e basi late ovata longe et anguste productis extus nudis glandulosisve intus pubescentibus apicibus dilatatis, fructu globoso pisi mole vertice infra lobos persistentes erectos constricto, stigmatibus liberis, acheniis dimidiato-oblongis dorso apiceque hirsutis.
R. pisocarpa, A. Gray in Proc. Amer. Acad. vol. viii. p. 382, and in Bot. Calif. vol. i. p. 187; S. Wats. Bibl. Ind. N. Amer. Bot. p. 313, and in Proc. Amer. Acad. Art. and Sc. vol. xx. p. 342.
R. nutkana? var. microcarpa, Crepin in Bull Soc. Bot. Belg. vol. xiv. p. 44,

To discuss the affinities of any rose, British or Exotic, is no light matter even for a specialist in the genus, and I hesitate to offer any opinion upon this little species, which in habit resembles no other known to me. At first sight it seems as different as roses are " inter se " from R. californica, which is a much larger, coarser, many-flowered species with recurved prickles ; but S. Watson, in his revision of the North American Roses, regards it as " rather doubtfully distinct from that plant, distinguished by the somewhat smaller and more globose fruit, and by the prickles never recurved, but frequently ascending."
R. pisocarpa was first described as a native of Oregon, and a specimen so named by Crepin was gathered by Douglas on the Columbia River in 1826, but as this is of a larger and coarser plant with ovoid fruit, I should refer it to R. califomica. Dr. Gray and I gathered it in the Upper Sacramento Valley, California, at an elevation of 4000 to 6000 feet in 1877, and it is probably not an uncommon plant in North California. Giay describes the calyx-lobes as reflexed, and the fruiting peduncle as nodding, which is not the case in dried specimens, nor in those that flowered at Kew. In the " Botany of California," it is further stated that the fruit is not constricted below the calyx-lobes, which it is very conspicuously. The Kew plants were raised from seed received from Prof. Sargent, and flowered in the Arboretum in July ; the fruit ripened in September.

Descr. A small, rather straggling, slender, much branched, nearly glabrous bush, unarmed or with small (rarely stout) straight or upcurved stipular spines. Leaves two to three inches long, petiole and rachis very slender, minutely pubescent. Leaflets two to three pair and an odd one, three-quarters of an inch long, broadly elliptic, obtuse, finely serrate, dark green but not shining above, paler and puberulous beneath ; stipules narrow, not leafy. Flowers one inch in diameter, solitary or in few-flowered corymbs, pedicel slender, rarely hispid. Calyx glandular; tube urceolate in flower; lobes very long, the broadly triangular ovate base contracted into a very slender lamina three times as long as the tube and slightly dilated at the tip, hoary within. Petals orbicular, two-fid, rose-coloured. Stamens very numerous, filaments short ; anthers pale yellow. Stigmas very shortly exserted, free. Fruit erect, globose, one-third to one-half of an inch in diameter, bright red, crown contracted into a neck beneath the long erect calyx-lobes. Achenes dimidiate- oblong, hirsute on the back and tip. — J. D. H.

Fig. 1, Calyx laid open, with stamens and carpels ; 2, carpels ; 3, ripe fruit of the natural size; 4, achene:— all but fig. 3 enlarged.