OPUNTIACEAE. 97 



1. P. suberosa L. Twigs glabrous or minutely pubescent: leaf -blades entire 

 to 3-lobed, mostly 2-10 cm. long: cymes 1-f ew-flowered : sepals linear to 

 lanceolate or oblong, 4-6 mm. long: corolla wanting: crown mostly blue-tinged: 

 berries 6-10 mm. in diameter: seeds about 3 mm. long. — Pinelands and ham- 

 mocks, U. keys, L. keys, L. S. keys. — [E. K.] — {Ber., Bah., Cuba, Ant.) 



2. P. multiflora L. Twigs velvety: leaf -blades oblong or nearly so, 5-12 cm. 

 long, entire, rugose beneath: sepals 5-6 mm. long: petals linear or nearly so: 

 berries subglobose, 6-8 mm. in diameter. — Hammocks, U. keys. — {Bah., Cuba.) 



Order OPUNTIALES. 



Succulent, typically spine-anned, herbs, shrubs, or trees, maiuly 

 leafless or essentially so, or leafy rigid herbs, with more or less specialized 

 hairs. Flowers perfect. Hypanthium present. Calyx of 4 or 5, or many, 

 sepals. Corolla of 4 or 5, or many, petals. Androecium of usually many 

 stamens, in several series or groups, sometimes partially reduced to 

 staminodia, Gynoecium of 4, or 2-several, united carpels. Ovaiy in- 

 ferior. Fruit baccate or capsular. 



Sepals and petals 4 or 5 each, very different : leaves with entire or dissected blades : 

 erect or ?limbing plants, with rigid hairs. Fam. 1. Loasaceae. 



Sepals and petals nearly alilie, at least the latter numerous : 

 leaves typically mere scales or wanting : succulent plants, 

 usually armed with spines. Fam. 2. Opuntiaceae. 



rA:iriLY 1. LOASACEAE. Loasa Family. 



Rigid herbs with barbed or stinging hairs. Leaves with entire lobed, 

 pinnatifid, or dissected blades. 



1. MENTZELIA [Plum.] L. Brittle-stemmed, mostly diffuse or reclining 

 herbs. Leaf-blades relatively broad, sinuate or lobed. Androecium without 

 staminodia. Seeds angled. 



1. M. floridana Nutt. Leaf -blades 2-9 cm. long, ovate to deltoid-ovate, toothed 

 and 3-lobed: sepals lanceolate, often very broad at the base: petals golden- 

 yellow, 15-18 mm. long: capsules 1-1.5 cm. long. — Hammocks, U. keys, L. keys. 

 — [E. K.]— (Baft.) 



Family 2. OPUNTIACEAE. Cactus Family. 



Succulent plants, typically spine-armed, and often with cushions of 

 bristles or hairs at the base of the spines. Leaves mostly wanting, obso- 

 lete, or rudimentary. 



Stems not jointed : leaves none or obsolete : areolae without barbed bristles : flowers 

 nocturnal : perianth campanulate. 

 Plants prostrate, reclining, or climbing : stems angled. 



Berry spiny : plants without aerial roots. 1. Acanthocereus. 



Berry scaly : plants with aerial roots. 2. Htlocekeus. 



Plants erect : stems and branches columnar, grooved. 



Flowers short-campanulate : periantli green-purple : 



style exserted : berry smooth. 3. Cephaloceeeus. 



Flowers long-campanulate : perianth white : style in- 

 cluded : berry scaly. 4. Haeeisia. 

 Stems jointed : leaves scale-like, deciduous : areolae with 



barbed bristles : flowers diurnal : perianth rotate. .5. Opuntia. 



1. ACANTHOCEREUS Britt. & Eose. Plants with erect or reclining 

 stems and branches, the 3-6 angles low, the areolae remote, with several spines 

 Flora of Florida Keys 7. 



