MELASTOMACEAE. 297 



yellow, about 7.5 cm. broad; ovary obovoid, with gloehide-bearing areoles; 

 petals obovate; stamens much shorter than the petals; fruit pyriform, red 

 or purple, edible, 5-8 em. long. 



Maritime and coastal rocks, Abaco and Great Bahama to Grand Turk and 

 Inagua : 'Bermuda; Florida: West Indies: eastern coast of Mexico. Bccordcd by 

 Hitchcock, Coker, Mrs. Northrop and Dolley, as O. Tuna (L.) Mill, and by Schoepf 

 as Cactus Tuna L. Common Prickly-pear. 



6. Opuntia Darrahiana Weber, Bull. Mus. Hist. Nat. Paris 10: 38S. 1904. 



Forming tufts 2-2.5 dm. high and 4 dm. in diameter, mueh-branehed. 

 Joints green, 7-8 cm. long, 4-5 cm. wide; areoles 1-2 cm. apart; glochides 

 none; spines about 6, the longer 4-4.5 cm. long, the shorter not more than 

 1 em. long, all white or grayish-white, brownish at the tip, straight, acieular, 

 rigid. 



Obtained by Darrah from Turk's Islands according to Weber : known to us only 

 from the description ; neither the flowers nor the fruit are described. Darrah's 



PRICKLY-PEAR. 



Order 21. MYRTALES. 



Herbs, shrubs or trees, unarmed, sometimes aquatic or amphibious. 

 Leaves alternate or opposite. Flowers regular or irregular, complete, and 

 often showy, or reduced to a stamen and pistil adnate to the hypanthium. 

 Hypanthium merely enclosing the ovary or adnate to it. Stamens few or 

 many. Anthers opening by slits, valves or pores. Stigma terminating the 

 style, or sessile. Fruit capsular or baccate, or resembling an achene. 



Style present, simple or compound ; stigma terminal. 



Anthers opening by pores. ,Fam. 1. Melastomaceae. 



Anthers opening by longitudinal valves. 



Hypanthium merely enclosing the ovary. Fam. 2. Lythraceae. 



Hypanthium adnate to the ovary or mainly so. 



Cotyledons spirally convolute in the embryo. Fam. 3. Terminaliaceae. 

 Cotyledons not spirally convolute. 



Sepals imbricated, or united and the calyx 



falling away as a cap. Fam. 4. Myrtaceae. 



Sepals valvate. 



Leaves stipulate; sepals leathery. Fam. 5. Rhizophoraceae. 



Leaves not stipulate ; sepals mem- 

 branous or herbaceous. Fam. 6. Onagraceae. 

 Style wanting; stigmas sessile. Fam. 7. Haloragidaceae. 



Family 1. MELASTOMACEAE R. Br. 



Meadow-beauty Family. 



Herbs, or many shrubs or trees in tropical regions, with opposite 3-9- 

 nerved leaves, and regular perfect often showy- but rarely odorous flowers. 

 Stipules none. Calyx-tube usually 4 5-lobed, the lobes imbricated. Petals 

 as many as the lobes of the calyx and inserted on its throat, imbricated. 

 Stamens twice as many, or equal in number to the petals, often inclined or 

 declined, the alternate ones sometimes shorter. Ovary 2-several-celled 

 (often 4-eelled) ; style terminal, simple; ovules oc , anatropous. Fruit 

 included in the calyx-tube, capsular or baccate. Seeds mainly small, with 

 no endosperm. About 150 genera and 2500 species, widely distributed in 

 tropical regions, most abundant in South America. 

 20 



