114 RHAMNACEvE. (BUCKTHORN FAMILY.) 



Ovules solitary, anatropous. Stigmas 2-5. Embryo large, with broad 

 cotyledons, in sparing fleshy albumen. — Flowers often polygamous, some- 

 times dioecious. Leaves mostly alternate : stipules small or obsolete. 

 Branches often thorny. (Slightly bitter and astringent : the fruit often 

 mucilaginous, commonly rather nauseous or drastic.) 



* Calyx and disk free from the ovary. 



1. Bercliemia. Petals sessile, entire, as long as the calyx. Drupe with thin flesh and a 



2-celled bony putamen. 



2. Rhamnus. Petals small, short-clawed, notched, or none. Drupe berry-like, with the 



2-4 separate seed -like nutlets concave on the back : cotyledons leaf-like, revolute. 



3. Frangula. Petals, &c. as in No. 2. Seed-like nutlets convex on the back : cotyledons 



flat, fleshy. 



* # Calyx with the disk adherent to the base of the ovary. 



4. Ceanotlius. Petals long-clawed, hooded. Fruit dry, at length dehiscent. 



1. BEECHEMIA, Necker. Supple-Jack. 



Calyx with a very short and roundish tube ; its lobes equalling the 5 oblong 

 sessile acute petals, longer than the stamens. Disk very thick and flat, filling 

 the calyx-tube and covering the ovary. Drupe oblong, with thin flesh and a 

 bony 2-celled putamen. — Woody high-climbing twiners, with the pinnate veins 

 of the leaves straight and parallel, the small greenish-white flowers in small 

 panicles. (Name unexplained, probably personal.) 



1. B. VOlubilis, DC. Glabrous; leaves oblong-ovate, acute, scarcely 

 serrulate; style short. — Damp soils, Virginia, and southward. June. — As- 

 cending tab 1 trees. Stems tough and very lithe, whence the popular name. 



2. RHAMNUS, Tourn. Buckthorn. 



Calyx 4 - 5-cleft ; the tube campanulate, lined with the disk. Petals small, 

 short-clawed, notched at the end, wrapped around the short stamens, or some- 

 times none. Ovary free, 2-4-celled. Drupe berry-like (black), containing 2- 

 4 separate seed-like nutlets, of cartilaginous texture, which are grooved on 

 the back, as is the contained seed. Cotyledons foliaceous, the margins revolute. 

 — Shrubs or small trees, with loosely pinnately veined leaves, and greenish 

 polygamous or dioecious flowers, in axillary clusters. (The ancient Greek 

 name, from the numerous branchlets.) 



* Lobes of the calyx, petals, and stamens 4. 



1. R. cathArticus, L. (Common buckthorn.) Leaves ovate, minutely 

 serrate; fruit 3-4-seeded; branchlets tborny. — Cultivated for hedges; spar- 

 ingly naturalized eastward. May, June. (Nat. from Eu.) 



2. R. lanceol&tus, Pursh. Leaves oblomj -lanceolate and acute, or on flow- 

 ering shoots oblong and obtuse, finely serrulate, smooth or minutely downy 

 beneath; petals deeply notched ; fruit 2-seeded. Hills and river-banks, Penn. 

 (Mercersburg, Prof. Green) to Illinois, and westward. May. — Shrub tall, not 

 thorny ; the yellowish-green flowers of two forms on distinct plants, both per- 

 fect : one with the short pedicels clustered in the axils and with a short in- 

 cluded style ; the other with the pedicels oftener solitary, the style longer and 

 exserted. 



