IQ2 LEGUMINOSJi. I'arkinsuuia. 



obliciuely or longitudiiuilly vuiued, thin-coriaceous, usually uioro or less torulose and 



compressed between the seeds. Seeds compressed, broadly oblong, longitudinal, 



albuminous ; hilum nanute. — Trees or shrubs, ol'ten armed with short spines : 



leaved bipinnatu with I or 2 pairs ol' i>innui j the conuuoji petiole short, often idiso- 



leto or spinescont ; 8ti[)ulob minute or none; Uowers yellow or whitish, on slejider 



pedicels in short loose axillary or terminal racemes. — Ctrcidium, Tulasne. 



A genus of 8 species, one of S. Africa, three of S. America (including P. acuhula which is 

 widely distributed through Uopicul America), the remainder bclonghig to the region between Texas 

 and b. Calit'oruia. 



* Leajlets usuaih/ very niivitruus, upon a iiiuchelufiyataljlatteaed r/uichis : divis- 

 tuHs of the calyx narrowly imbricate in the bud. 



1. P. aculeata, Linn. A small tn-e, glabrous throughout, the slender branches 

 often pendulous : spiny petioles a half Ut an inch long or less, bearing 1 or 2 pairs of 

 piiinne near the base, or wanting ; leatluts very small, oblong, scattered upon a broad 

 rhachis ^ to 1^ feet long; stipules small, spinesceiit : racemes axillary 3 to G inches 

 long : peilicels jointed a little below the llower : stamens shorter than the yellow 

 petals : pod 2 to 10 inches long, I - 5-seeded, attenuate at eacli end and contracteil 

 between the distant seeils. — iJejitli. in Mart. Fl. liras. xv*. 78, t. 2G. 



Hills of the Colorado near Fort Yuma, and througli Mexico to Texas. Piohably of American 

 origin, but now naturalized or cultivated in most of the tropical and warmer regions of tin- globe. 



* * P in ace ahurt and leajlets Jew ; rhachis terete : calyx valvate in the bud. 



2. P. microphylla, Torr. A much-branched shrub, 5 to 10 feet high, with 

 smooth light-green hark, the straight rigid branchlets si)inose at the ends ; younger 

 branches and inflorescence somewhat puberulent : common ])etioles very short or 

 none, not spinescent or rarely so ; leaflets 4 to G pairs in each pinna, broatlly oblong 

 or nearly orbicular, obtuse or acutish, not narrower at the obliqmi base, two lines 

 long or less, glaucous: racemes short (an inch long or less), axillary and sessile; 

 l)ediceld evidently jointeil a little below the llower: petals ileep straw-color, the 

 tipper one white, iJ tu' 4 lim;s long : anthers orange, ex.serted : ovary ap})ressed- 

 silky : pod attenuate at each end, 1 - 3-seeded, contracted between the seeds, 2 or 3 

 inches long. — J3ot. Mex. Bound. 59 ; Benth. 1. c. 



On the Colorado near Fort Yuina, on Bill Williams River, and eastward through S. Arizona ; 

 flowering in Ahiy. 



3. P. Torreyana, Watson. A small tree, 20 or 30 feet high, with light green 

 and smooth bark ; younger branches and leaves sparingly j)ubescent : leallets 2 or 3 

 pairs, oblong, obtuse, narrower toward the scarcely obli([Ue base, 2 or 3 lines long, 

 glaucous : flowers on longer pedicels in racemes terminating the branches: pedicels 

 jointed near the middle, the joint not evident until in fruit: petids 4 lines hm^^, 

 apparently bright yelhjw ; ghin<l up(ni the upper petal very ])roniinent : ovary gla- 

 brous : pod 2 or 3 inches long, with a double groove along the broad vential suture, 

 acute, 2 - 8-seeded, scarcely or decidedly contracted between the very thick seeds. 



— Proc. Auj. Acad. xi. 135. Cercidium Jhridum, Torrey, Pacif. 11. Kep. v. 300, 

 t. 3 ; not of ]ienth. 



A frciiuent treoin tiic Valley tif tlio Colorado and eastward ; tlio Pulo J'cntt; vi Ww Mexicans, 



— usually bare of foliage, the leaves l)eing .soon dc(i<luons. Tin! specicis has been mistaken l<jr 

 the /•*. Jlorida (^Cercidium Jloriduiii, Henth.) of the liio Grande Valley, which bus axillary 

 racemes, pods with a narrow acute margin on the ventral -side, thinner seeds, and somcwbal larger 

 leaflets. 



20. PROSOPIS, hinn. Miisyurr. Sc^uiiw-uicAN. 



Flowers regular. Calyx campanulate ; the teeth very short, valvate. Petals 5, 

 valvate, united below the middle or at length free, Nvoolly on the inner side (in our 



