114 RHAMNACE^E. (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. Kluiniiius. 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. Ceanothus. Petals long-clawed, hooded. Fruit dry, at length dehiscent. 



1. BERCHEMIA, 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 fiat, 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. voltlbilis, DC. Glabrous; leaves oblong-ovate, acute, scarcely 

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

 cending tall 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 thorny. Cultivated for hedges; spar- 

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



2. R. lanceol&tus, Pursh. Leaves oblong-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. 



