Part 2, 1910] ZYGOPHYLLACEAE 107 



4. Guaiacum Coulteri A. Gray, Mem. Am. Acad. II. 5 : 312. 1855. 



Guaiacum a/rum Sesse & Moc. Fl. Mex. 118. 1894. Not G. a/rum L. 1753. 



Shrub 1-3 in. high; leaves 3-6 cm. long; leaflets 6-10, linear-oblong, 1-2.5 cm. long, 

 4-8 mm. wide, mucronate, glabrous, coriaceous, minutely veiny; petioles and rachis 

 pubescent; stipules subulate; flowers axillary, 3-9 or more; pedicels 10-15 mm. long, 

 slender, pubescent; sepals 5, 4-6 mm. long, unequal, broadly oblong or oblong-orbicular, 

 rounded at the apex, minutely pubescent on the inner surface ; petals 5, blue, obovate, 

 9-15 mm. long, 5-7 mm. broad ; ovary 5-celled, narrowly obovate, compressed, glabrous ! 

 style short, persisting; filaments filiform from a broad flat base; anthers 3 mm. long; 

 fruit greenish, 5-carpellary or by abortion 2-4-carpellary, obcordate, 12-15 mm. long, 17 

 mm. broad, retuse, mucronulate, the carpels carinate on the back ; seed ellipsoid, 10-12 

 mm. long, 6-7 mm. wide, brown, covered with a pale-yellowish aril ; endosperm white, 

 very thick, bony; cotyledons flat, very thin, bright-yellow, oblong or ellipsoid, 6 mm. 

 long, 4 mm. broad. 



Type locality : Hills between Rayon and Ures, Sonora. 

 Distribution : Sonora, Sinaloa, Guerrero, Tepic, and Oaxaca. 



5. Guaiacum Planchoni A. Gray, sp. nov. 



Guaiacum parvifolium Planch.; A. Gray, PI. Wright. 1 : 29, hvponym. 1852. Not G. parvifolium 



Nutt. 1849. 

 Guaiacum Planchoni A. Gray, Proc. Am. Acad. 22 : 306, as a synonym. 1887. 

 ? Guaiacum sanctum f. angustifolia Engler, in Loes. Bull. Herb. Boiss. II. 3 : 96. 1903. 



Much branched shrub, 2-3 m. high, with grayish corky bark ; leaves crowded or 

 fascicled on short modified branchlets, about 15 mm. long ; leaflets 4-8, linear or linear- 

 oblong, 8-12 mm. long, 1.5-2 mm. wide, apiculate, glabrous, coriaceous ; petioles and 

 rachis pubescent ; stipules subulate, minutely pubescent ; flowers apparently solitary at 

 the ends of the branchlets ; peduncles 8-12 mm. long, slender, minutely pubescent ; bracts 

 subulate ; sepals 5, oblong, obtuse, unequal, 6-7 mm. long, ciliate, barely pubescent outside, 

 distinctly so within ; petals 5, blue, very thin, obovate, 10-12 mm. long, tapering at the 

 slender base ; filaments 7-8 mm. long, filiform, barely broader at the base ; anthers narrowly 

 oblong, 2 mm. long; ovary 5-celled, narrowly obovate, 5-winged, glabrous, tapering at both 

 ends; fruit not seen. 



Type collected between Tehuantepec and the Pacific Ocean, Oaxaca, G. Andrieux 475 (herb. 

 Kew and herb. N. Y. Bot. Gard.). 



Distribution : Known only from the type locality. 



6. Guaiacum Palmeri Vail, sp. nov. 



A shrub or small tree (?) with corky bark, and numerous short modified branchlets ; 

 leaves fascicled at the ends of the branchlets, 15-20 mm. long ; leaflets 4-6, mostly 6, 

 linear-oblong, 4-10 mm. long, 2-3 cm. wide, obtuse, apiculate, coriaceous, reticulate, 

 glabrate above, obscurely pubescent beneath ; petioles and rachis densely pubescent ; 

 stipules subulate, minute, pubescent ; flowers 1-3, borne on peduncles 1 cm. long, produced 

 mostly in the axils of the leaves at the ends of the branchlets ; sepals 5, oblong or obovate, 

 about 6 mm. long, minutely pubescent, on the inner surface ; petals 5, blue, broadly orbicu- 

 lar-obovate, about 1 cm. long, thick, very slender at the unguiculate base ; ovary broadly 

 obovate, stipitate, 5-angled, tomentose, abruptly contracted into the short tomentose style ; 

 filaments filiform from a broader flat base ; anthers oblong, 2 mm. long ; fruit broadly 

 obovoid, 10-15 mm. long, 10-15 mm. broad or more, stipitate, yellowish-green, cori- 

 aceous, minutely pubescent, 5-valved and angled, carinate on the angles ; seeds 2-3, 7-8 

 mm. long, elliptic, covered with a dark-red (?) fleshy aril ; endosperm bony, not very thick ; 

 cotyledons 3-4 mm. long, oblong, 2 mm. broad, dark-green. 



Type collected at Guaymas, Sonora, 1887, E. Palmer 113 (herb. Columbia Univ.). 

 Distribution : Known only from the type locality and vicinity. 



