238 CUCURBIT ACE^E. Petalonyx. 



toothed, the upper sessile, the lower on rather short petioles : flowers large, on 

 pedicels 3 to 6 lines long, in terminal bracteate cymes : calyx-lobes lanceolate, 6 to 

 10 lines long; petals twice longer, broadly spatulate, abruptly acuminate, hairy at 

 the apex, united at base into a tube 3 lines long : filaments equalling the calyx- 

 lobes : style stout, cleft to the middle : capsule broadly obovoid, half an inch long, 

 opening by 5 erect valves as in the other species; the seeds also exceedingly numer- 

 ous, linear-oblong, about a fifth of a line long, marked by a few longitudinal stride. 

 Am. Naturalist, ix. 144. Mentzelia urens, Gray, Proc. Am. Acad. x. 71, Am. 

 Naturalist, ix. 271. 



Collected by Bigelow in rocky arroyos near the confluence of the Williams River with the Colo- 

 rado, and eastward to Southern* Utah, Parry. 



3. PETALONYX, Gray. 



Calyx-tube very small, cylindrical, with 5 linear deciduous lobes as long as the 

 ovary. Petals 5, with long conriivent claws and ovate-spatulate blade. Stamens 5, 

 with free filiform filaments, inserted with the petals on the outer edge of an epigy- 

 nous disk ; anthers small, didymous. Ovary 1-celled : style simple, elongated : 

 stigma entire : ovule solitary, pendulous from the summit of the cell. Capsule very 

 small, oblong, bursting irregularly. Seed oblong, smooth. Erect perennial herbs, 

 or shrubby at base, pubescent or rough with short barbed hairs; leaves alternate, 

 entire or toothed; flowers small, yellowish, in terminal heads or short leafy spikes. 

 Three species, of Arizona and the adjacent region. 



1. P. Thurberi, Gray. Stems 1 to 2 feet high from a somewhat woody base, 

 branching : leaves ovate to oblong, an inch long or less, smaller and becoming bract- 

 like (2 to 3 lines long) on the branches, sessile, acute, entire or rarely few-toothed ; 

 the floral bracts ovate, acuminate, toothed at base : flowers in short and dense 

 spikes, sessile : calyx 2 lines long : petals light yellow, 2 lines long or more, slightly 

 hispid : filaments and style half an inch long : capsule a line long, not angled or 

 winged. PI. Thurb. 319 ; Torrey, Bot. Mex. Bound, t. 22. 



San Diego and San Bernardino counties, and adjacent parts of Arizona to S. Nevada, Thur- 

 ber, Cooper, Schott, Palmer, &c. 



P. NITIDUS, Watson, is found in S. Nevada and probably extends into S. E. California ; dis- 

 tinguished by its ovate petioled coarsely toothed leaves, rounded at base, not greatly reduced on 

 the branches, and with a somewhat vitreous and shining surface. 



P. PARKYI, Gray, is a more eastern species, of S. Utah, decidedly shrubby, the leaves rhom- 

 boidal-ovate, cuneate into a short petiole, scarcely smaller above. 



ORDER XLI. CUCURBITACE#3. 



Herbs, mostly tendril-bearing and climbing, rather succulent, with alternate and 

 palmately veined or lobed leaves, no proper stipules; the flowers monoecious or dioe- 

 cious, with petals more commonly united into a cup or tube and also blended with 

 the calyx. Sterile flowers with 2^ stamens, that is, two complete, with 2-celled 

 anthers, and one with a 1-celled anther; the cells usually long and contorted. Fer- 

 tile flowers with calyx-tube adnate to a 1-celled or 2 - 3-celled ovary ; the placentae 

 either parietal, or confluent in or projecting from the axis. Seeds anatropous, with- 

 out albumen. 



A peculiar but familiar family, of great diversity as to the fruit, &c., yet easy to recognize, 

 widely distributed over the world, but mainly indigenous to warm regions. Chiefly important 

 for the esculent fruits it produces (Melon, Watermelon, Cucumber, Pumpkin, Squash, &c.), and 



