202 CONTEIBUTIONS FROM THE NATIONAL HERBARIUM. 



24. MORACEAE. Mulberry Family. 



Usually trees, with milky sap; leaves alternate, entire, dentate, or lobate, the 

 stipules deciduous ; flowers very small, monoecious or dioecious. 



The only other Mexican genus is Dorstenia, whose species are low herbs. 

 Toxylon pomifeium Raf., the Osage orange or bois d'arc (known in Chihuahua 

 as " naranjo chino"), native of the southern United States, is sometimes culti- 

 vated. It is a very spiny tree or shrub, with globose yellowish fruits sometimes 

 15 cm. in diameter. Artocarpus communis Forst., the breadfruit tree of the 

 Pacific islands ("^.rbol del pan "), with large, pinnately lobed leaves and large 

 rough fruit, is in cultivation in tropical Mexico. 



Leaves peltate, the blades radiatcly lobed. Flowers in dense spikes. 



9. CECE.OPIA. 

 Leaves not peltate, the blades not radiately lobed. 

 Flowers borne on the .inside of a globose receptacle, this fleshy, with a small 



opening at the top 4, FICUS. 



Flowers not borne inside a receptacle. 



Flowers of one or both sexes in aments, spikes, or racemes. 

 Pistillate flowers in spikes or aments. 



Pistillate perianth of distinct segments ; fruit very juicy, with a small 



seed, naked 2. MORTJS, 



Pistillate perianth tubular; fruit with only thin flesh, with a large 



seed, covered by the accrescent perianth 3. TROPHIS. 



Pistillate flowers in heads. 



Staminate flowers with a 4-parted perianth 1. CHLOBOPHOBA. 



Staminate flowers without a perianth 8. SAHAGUNIA. 



Flowers of one or both sexes capitate, borne on a flat or rounded recep- 

 tacle, or solitary. 

 Leaves very densely long-hairy ; flowers borne on a flat receptacle. 



7. CASTILLA. 

 Leaves never densely long-hairy ; flowers not borne on a flat receptacle. 

 Pistillate flowers sessile and usually solitary in the axils. 



6. PSEUDOLMEDIA. 

 Pistillate flowers in heads or on a receptacle. 



Pistillate flowers one on each receptacle 5. BBOSIMUM. 



Pistillate flowers more than one to each head or receptacle. 

 Inflorescence wholly of heads; leaves entire — 10. COUSSAPOA. 

 Inflorescence partly of spikes (staminate) ; leaves usually toothed. 

 Staminate flowers wtih a 4-parted perianth. 



1. CHLOBOPHOBA. 

 Staminate flowers without a perianth 8. SAHAGUNIA. 



1. CHLOBOPHOBA Gaud, in Freyc. Voy. Bot. 508. 1826. 



Leaves glabrous or nearly so 1. C. tinctoria. 



Leaves densely pubescent on both surfaces 2. C. mollis. 



1. Chlorophora tinctoria (L.) Gaud, in Freyc. Voy. Bot. 508. 1826. 



Morus tinctoria L. Sp. PI. 986. 1753. 



Chiefly on stream banks and seashores, San Luis PotosI to Yucatan and 

 Tabasco; reported from Tamaulipas, Oaxaca, Michoacan, and Guerrero. Cen- 

 tral America, West Indies, and tropical South America ; type from Jamaica. 



Shrub or tree, sometimes 20 meters high, with a trunk 10 to SO cm. in 

 diameter, the bark brownish gray or light brown, with few shallow furrows, 

 the branches spreading, often armed with sharp axillary spines; leaves 

 deciduous, ovate or oval, caudate-acuminate, bright dark green, entire or ser- 



