356 ZYGOPHYLLACE.E. Guaiacum. 



Z;/gophyllum tridentatum, Moc. & Sesse ace. to DC. Prodr. i. 706; A. DC. Caiques des Dess. 

 t.i59.i_ Arid districts, S. Texas^ to S. Utah and S. California; ti. summer. (Mex.) 



5. G-UAIACUM, Plumier. Lignum-vit.e. (Aboriginal name.) — Trop- 

 ical and subtropical American trees or shrubs, with very hard and heavy resinous 

 wood, abruptly pinnate somewhat coriaceous leaves, and blue or purplish solitary 

 or umbellate-fascicled flowers. — Nov. Gen. 39, t. 17; L. Gen. no. 39-4; Gray, 

 Gen. 111. ii. 121, t. 148, 149. — Name also written Guajacum, which, however, 

 was not the original form. 



§1. Filaments naked : branchlets much articulated : leaflets comparatively 

 large and few, obovate to elliptical. 



G. sanctum, L. (Oue of tlie two kinds of Lignum-vitce, yielding Gum Guaiacum). Small 



tree : leaflets 3 or 4 or rarely 5 pairs, obovate-obloug or elliptical and oi)li<iue, inch or less 



long : petals very short-unguiculate, quarter to tliird inch long, double tlie length of the 



glabrous sepals :' fruit short-stipitate, obovate in outline, wing-angled, abruptly pointed, 



usually all five carpels maturing. — Spec. i. 382 ; Gray, Gen. 111. ii. 123, t. 148 ; Nutt. Sylv. 



iii. 17, t. 86 (var. parvifolium, a small-leaved form) ; Griseb. Fl. W. Ind. 134 ; Sargent, U. S. 



10th Census, ix. 28.8 (;. vertlcale (Ort. Dec. viii. 93 ?), A. Rich. Fl. Cub. 321. G. Sloium, 



Shuttl. in distr. pi. Rugel, no. 68, 69. — Keys of Florida. (W. Ind.) 



§ 2. Filaments with a small scale at or near the base : leaflets approximate. 



comparatively small, narrow, and more numerous ; stipules in our species small 



and subspinescent. — Porlieria, Ruiz & Pav. Prodr. oo, t. 9. Guaiacum § Guaia- 



cidium, Gray, 1. c. 124, t. 149. 



G. Coulteri, Gray. Shrub 8 to 10 feet high : leaves 3 to 5 pairs, linear oblong, obscurely 

 veinv, half inch long : fruit 4-5-coccous, retuse at both ends, mucronulate, half inch high ; 

 the carpels merely carinate on the back. (Flowers not seen.) — PI. Thurb. 312. — Below 

 boundary of Arizona, in Sonora, between Rayon and Ures, Thurber. (Mex., Th. Coulter* 

 but needs comparison.) 

 G.* angUStifolium, Engelm.s Much-branched shrub or small tree, with spinescent 

 branches : leaflets 4 to 8 pairs, oblong-linear or linear-spatulate, quarter to half inch long, 

 reticulated : flowers mostly single, very short-peduncled, 5-merousor occasionally 4-merous: 

 filaments with a short .scale at base : ovary 2-celled : fruit somewhat obcordate-bilobed, cari- 

 nate-margined. — Kugelm. in Wisliz. 1. c. 113 (p. 29 of reprint) ; Gray, PI. Lindh. pt. 2, 158, 

 & Gen. 111. ii. 124, t. 149. Porlieria ancjustifolia. Gray, PI. Wright, i. 28; Torr. Bot. Mex. 

 Bound. 42. — S. and W. Texas from the Colorado south and west to the Pecos; where first 

 coll. by Lindheimer. (Mex., first coll. by Berlandier.) 



1 The nearly related S. American L. divaricnta, Cav., with which this species has recently been 

 united (see A. M. Vail, Bull. Torr. Club. xxii. 229), has, in the four s])ocimens at hand, more narrowly- 

 oblong and more widely spreading leaflets, which are less inclined to be falcate and are more decidodly 

 connate. In herb. Gray, there is, on the other hand, a specimen collected by .yncra and labelled 

 " Int. Buenos or Chili," which is without doubt identical with /.. ^fexicnnn. The following synonymy 

 may be added to our own species: L. trir/entata, Coville, Contrib. U. S. N.it. Herb. iv. 75. Zyfioihijl- 

 lum C(difornicum, Torr. & Frem. in Frem. Kep. 257, ace. to Coville. CoviUea divaricata, A. M. Vail, 

 1. c, not L. divaricata, Cav. 



2 Northward to S. Colorado, acc. to Coulter, Man. Rocky Mt. Reg. 43. 



3 Add Silv. i. 63, t. 28. 



* Also about Guavmas, Mex., Palmer. 



5 This species is referred to by Dr. Gray, Proc. Am. Acad. xxii. 306, as " G. parvifoUum," while 

 G. parvifolium, Planchon, was unnecessarily given a new name, G. Ptanchoni, Gray, which must fall 

 into synonymy. 



