THE CALTROP FAMILY 



ZYGOPHYLLACEiE Lindley 



|]YGOPHYLLACE^ consists of about 20 genera including some 150 

 species of herbs, shrubs and trees, widely distributed in warm and 

 tropical regions. They have opposite stipulate pinnate leaves with 

 entire leaflets. Their flowers are regular, perfect and stalked, either 

 axillary or terminal, and solitary or clustered; there are usually 5 sepals and 5 

 petals and twice as many stamens as there are petals, the stamens having ver- 

 satile anthers; the ovary is several-celled, with either one or several ovules in each 

 cavity; the united styles are terminal. The fruit, in our species, is nearly dry, 

 capsular, spUtting when ripe into two carpels or more. 

 The North American tree genera are : 



Filaments not appendaged; leaflets broad. i. Guaiacum. 



Filaments appendaged; leaflets narrow. 2. Porliera. 



LIGNUM VITiE 



GENUS GUAIACUM [PLUMIER] LINN.EUS 

 Species Gnaiacmn sanctum Linnaeus 



HE genus Guaiacum contains several species of trees and shrubs, with 

 evergreen leaves, widely distributed in the American tropics. G. sanc- 

 tum inhabits southern Florida, growing on several of the Keys, and 

 occurs throughout the Bahamas, in Porto Rico, Haiti, Cuba, and Yu- 

 catan., The generic name is Carib; Guaiacum officinale Linnaeus is the type. 



The tree attains a maximum height of about 10 meters, with a short trunk 

 up to I meter in diameter; on the Bahamas it sometimes blossoms as a mere shrub. 

 The thin bark is light gray, separating on the surface into thin scales; the branches 

 are irregular, spreading or somewhat drooping, isolated trees being nearly round 

 in outline, or even broader than high. The young twigs and leaves are slightly 

 hairy, but soon become smooth; the branchlets are much thickened at the nodes, 

 light gray and somewhat ridged. The leaves are petioled and have 3 or 4 pairs 

 (occasionally only 2 pairs) of leathery oblong or obovate leaflets, which are blunt 

 or minutely tipped, sessile or nearly so, finely veined, with veins radiating from 

 the base, 3 cm. long or less, dark green on both sides. The beautiful flowers are 

 borne at the ends of twigs, their slender hairy peduncles minutely bracted at the 

 base, and appear from February to April; the hairy sepals are shorter than the 



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