134 RUTACEiE. 



LXVIIL ZYG0PHYLLEJ3. 



Sepals distinct. Petals mostly imbricative. Stamens 2(-l)-seriate, distinct. Pistil 

 syncarpous : styles combined. Embryo straight, with the cotyledons plane : albumen 

 corneous or none. — Leaves stipulate, usually compound and opposite, devoid of pellucid 

 dots. 



The celebrated alterative gum-resin, Guajacum, is obtained from the wood of both the 

 West Indian species of the genus so called ; this wood, named Lignum Vita, is very hard 

 and heavy, its specific gravity being 1*3. 



1. TRIBULUS, L. 



Sepals 5 (-6). Stamens 10 (-5). Pericarp 5-10(-12)-coccous : carpids indehiscent, 

 tubercled or spinose. Embryo exalbuminous. — Herbs ; leaves abruptly pinnate, opposite. 



Sect. 1. Eutribuiajs. — Calyx deciduous. Carpids 5, divided internally by transverse 

 dissepiments into 1-seeded compartments. 



1. T. cistoides, L. Perennial; leaflets 8(-3)-jugal, silky beneath, shortly oblong; 

 peduncles as long as the leaf, 1 -flowered ; sepals lanceolate, acuminate, half as long as the 

 petals; stamens 10; carpids 5-3-seeded, leaving by their separation no central axis, 

 tubercled, and 2-1-spinose : spines divergent. — As. Gr. Gen. 2. t. 145 ; Desc. Fl. 4. t. 250. 

 — Petals yellow, 8"'-10'" long, imbricative. — Hab. Jamaica !, Dist., common in the southern 

 salt-pastures ; [tropical seashores of all continents, Florida, Texas, Cuba !, and Mexico to 

 Venezuela !, Cape Verde Islands !, Mozambique !, East Indies !, Sandwich Islands !, Gala- 

 pagos!]. 



Sect. 2. Kallstkcemta. — Calyx persistent. Carpids 10 (-12), separating from the 

 central axis, 1-seeded. 



2. T. maximns, L. Annual, suffrntescent, prostrate; leaflets 3-4(-2)-jugal, hairy 

 beneath, obliquely oblong or oval : stipules lanceolate-linear ; peduncles nearly as long as 

 the leaf; sepals subulate, a little exceeded by the petals ; stamens 10; carpids keeled, 

 tubercled, unarmed.— SI. t. 132. /. 1 ; Br. Jam. t. 21. /. 3 ; As. Gr. Gen. 2. t. 146.— 

 T. decolor, Macf. ! Kallstrceinia, Torr. et Gr. — Petals pale-tawny, 2" -3'" long ; twisted. — 

 Hab. Jamaica !, Dist., Al., common in pastures ; S. Vincent I, Guild. ; [Texas !, California !, 

 Mexico !, Panama !]. 



2. GUAJACUM, L. 



Sepals 5. Stamens 10 : anthers recurved. Ovary stipitate : cells 8-10-ovulate. Peri- 

 carp somewhat fleshy, 5-2-celled, tardily septicidal: cells 1-seeded by abortion, compressed 

 and keeled. Embryo included within a rimose albumen. — Trees or shrubs ; leaves abruptly 

 pinnt 1 ^ opposite, coriaceous, glabrous ; peduncles 1-3, terminal, \-flowered ; petals blue. 



3. G. officinale, L. Leaflets 2^'ugal, obovate or oval, blunt ; sepals oval, pubescent, 

 3 times exceeded by the petals ; fruit obovate-roundish, retuse, — SI. t. 222. f. 3-6 ; Tuss. Fl. 

 4. t. 35 ; Desc. Fl. 7- t- 463. — A middle-sized or low tree ; leaflets 12'"-6"' long, evergreen ; 

 petals spathulate, 6'" long. — Hab. Jamaica!, Macf., Pd., Al., March, in the arid southern 

 plains, to Trinidad !, Lockh. ; [Cuba to Venezuela !]. 



4. G. sanctum, L. Leaflets §-4t-jugal, obliquely lanceolate-elliptical, or obovate, 

 pointed or blunt ; sepals oval, glabrous, half as long as the petals ; fruit obovate-roundish, 

 mucronate. — Commel. Ht. t. 88 ; As. Gr. Gen. 2. t. 148. — G. verticale, Bach. Cub. — 

 Leaflets 12"'-8'" long; petals obovate, 6'" long. — Hab. Bahamas !, Swains. ; [Key-West, 

 Cuba, Haiti !, Portorico]. 



XLIX. RUTACE^E. 



(Diosmese, Zanthoxylese, Simarubese.) 



Stamens usually 2-1 -seriate. Pistil syncarpous,- with the ovaries usually distinct above : 

 ovules 2 (1 -several) in each cell. Pericarp capsular and mostly divided into distinct, follicular 



