750 FRANGULACEAE 



spikes slender, 1-4 cm. long, sometimes compound: calyx 2-2.5 mm. broad : sepals tri- 

 angular acute, slightly longer than the tube : petals 5, orbicular-ovate, emarginate, very 

 short-clawed, about 5 as long as the sepals : stamens 5, about as long as the petals : drupes 

 subglobose, often gibbous, 7-9 mm. in diameter. [/S. Michauxii Brongn.] 

 Near the coast, North Carolina to Florida and Alabama. Spring. 



8. RHAMNUS L. 



Shrubs or trees, with unarmed branchlets. Leaves alternate : blades entire or toothed : 

 stipules deciduous, many-nerved. Flowers perfect or polygamo-dioecious, axillary, often 

 clustered, or in racemes or cymes. Sepals 4-5, keeled within, triangular-ovate. Disk 

 lining the hypanthium, cup-like. Petals 4-5, or wanting, clawless, inserted on the margin 

 of the disk, commonly concave, shorter than the calyx. Stamens 4-5, inserted on the 

 edge of the disk : filaments very short. Ovary 3-4-celled, nearly free : styles 2-4, united 

 at the base : stigmas often 2. Berry drupe-like, Avith 3-4 long or cartilaginous nutlets. 

 Seeds elongated, with a membranous or crustaceous, smooth or furrowed testa. Endo- 

 sperm fleshy. Buckthorn. 



Flowers usually dioecious : nutlets deeply grooved on the back : raphe dorsal : cotyledons leaf-like. 



1. R. lancealata. 

 Flowers perfect : nutlets not grooved : raphe lateral : cotyledons thick. 2. R. Caroliniana. 



1. Rhamnus lanceolata Pursh. A shrub 1-2 m. tall, with puberulent branchlets 

 and a smooth grayish bark. Leaf-blades firm, oblong or oblong-lanceolate or sometimes 

 oval, acute or acuminate, serrulate, abruptly acute or rounded at the base, short-petioled : 

 clusters 2-3-flowered : pedicels 2-6 mm. long : calyx about 3 mm. broad ; sepals usually 4, 

 triangular-ovate, acute, about as long as the tube : petals suborbicular in outline, deeply 

 notched at the apex, about one-half as long as the sepals : stamens as long as the petals : 

 anthers obtuse : fruits globular, 5-7 mm. thick, 2-seeded : seeds furrowed on the back. 



On river banks and moist hillsides, Pennsylvania to Iowa, Alabama, Texas and Colorado. Spring. 



2. Rhamnus Caroliniana Walt. A shrub or small tree, reaching a height of 11 m. 

 and a trunk diameter of 20 cm., clothed with an ash-gray bark. Leaf -blades firm, oblong 

 or elliptic or often slightly broadest above the middle, 5-12 cm. long, acute or short- 

 acuminate, commonly slightly revolute, undulate or serrulate, abruptly pointed or rounded 

 at the often inequilateral base, short-petioled, densely tomentose or becoming glabrous : 

 umbel-like clusters few-flowered : calyx 4 mm. broad ; sepals 5, triangular-ovate, acute, 

 slightly shorter than the hypanthium : petals 5, notched at the apex, about ^ as long as the 

 sepals : stamens 5, nearly as long as the petals : fruits subglobose, 10-11 mm. thick, black, 

 3-seeded : seeds smooth on the back. 



On river banks and hillsides, Virginia to Missouri, Kansas, Florida and Texas. Spring. Indian 

 Cherry. Yellow-wood. Polecat-tree. 



9. CEANOTHUS L. 



Shrubs or small trees, often armed with spines. Leaves alternate, rarely almost scale- 

 like : blades commonly 3-ribbed : stipules minute, caducous. Flowers perfect, crowded in 

 terminal panicels or thyrsoid cymes or umbels. Hypanthium hemispheric or urn-shaped. 

 Sepals 5, white, often triangular-ovate, membranous, converging, deciduous. Disk fill- 

 ing the hypanthium. Petals 5, inserted under the disk : blades long-clawed, protruding 

 between the sepals, strongly hooded. Stamens 5, exserted : filaments filiform. Ovary 

 immersed in the disk, somewhat cohering, or distinct, 3-celled : styles short, united 

 below : stigmas 3, terminal or lateral. Drupe berry-like, 3-lobed, with a thin epicarp, sep- 

 arating into 3 crustaceous, or cartilagenous nutlets. Seeds flattened, with a smooth crusta- 

 ceous testa. Endosperm fleshy. 



Leaf-blades entire, fleshy. 1. C. microphyllui. 



Leaf-blades toothed, membranous or nearly so. 



A low decumbent shrub: leaves 5-10 mm. long, persistent. 2. C. serpyllifolius. 



Erect shrubs : leaves deciduous. 

 Common peduncles abbreviated. 



Twigs and branchlets viscid-puberulent : lower surfaces of the leaf-blades 



glabrous or with few scattered hairs. 3. C. ovatus. 



Twigs and branchlets copiously pubescent : lower surfaces of the leaf-blades 



closely and permanently pubescent. 4. C. pubescens. 



Common peduncles elongated. 



Leaves 1-3 cm. long. 5. C. intermedius. 



Leaves 3-10 cm. long. 6. C. Americanus. 



