CXCVII. BETULACE^. 677 



persistent. Stamekts inserted at the bottom of the perianth, equal and opposite to 

 its lobes, rarely more numerous ; filaments filiform, distinct ; anthers 2-celled, 

 dorsifixed; cells somewhat oblique, introrse, dehiscence longitudinal. Ovabt free, 

 of 2 connate carpels, 2-celled {Ulmus) or 1-celled (Planera) ; styles 2, divergent, 

 stigmatiferous along their inner face ; ovules solitary in each cell, pendulous near 

 the top of the septum, or from the top of the single cell, anatropous. Fruit a 

 membranous samara {Ulmus), or a coriaceous 1-celled and 1-seeded indehiscent 

 nut {Planera). Seed inverted, testa membranous, raphe longitudinal. Embryo 

 exalbuminous, straight; cotyledons plane {Ulmus) or sub-sinuous {Planera), or con- 

 duplicate {Holoptelea) ; radicle short, superior. 



GENEEA. 

 * Ulmus. * Planera. Holoptelea. 



By many botanists Ulmacece are united with Celtidecs, from ■which they only differ in their inflores- 

 cence, extrorse anthers and anatropous ovule; hoth are included in the class Ueiiciitb^ of Brongniart 

 and adopted by Planchon ; for in tflmacem, though the ovule is anatropous, the micropyle faces the top of 

 the ovary, as in the other families of Urticinece. 



Ulmacete are spread over the temperate northern regions [and sub-tropical India]. Their bark con- 

 tains an astringent and tonic bitter mucilage and tannin. The inner bark of the common Elm (JIhnus 

 campestris) has been considered a remedy for dropsy and eruptions. That of the American Elms ( TI. 

 fulva and americana) is so rich in mucilage that poultices and a nutritious jelly are made of it. The 

 Americans reduce it to a powder as fine as flour, and employ it largely in inflammatory diseases. Planera 

 Abelicea, a native of Crete, produces an aromatic wood, formerly exported under the name of False 

 Sandalwood. Elm wood is rather hard, reddish, and used especially for wheelwright's work, shafts, 

 axle-trees, screws for presses, &c. Exostoses or wens are often developed on Elm trunks, which acquire 

 gTeat hardness, and are much sought by cabinet-makers from the different patterns the twisted arrange- 

 ment of their wood-fibres exhibits. 



CXCVII. BETULACEJE. 



(Amentacearum genera, Jussieu. — BetulIn^, L.-C. Richard. — Betulace^, Bartling.) 



Flowers monoecious, in catkins, the $ with a calyciform scale-like perianth, the 

 9 achlamydeous, with accrescent scales. Stamens 4 or 2. Otaet with two 2-ovuled 

 cells ; OVULES pendulous, anatropous. Nuts usually winged, 2-celled, 1-seeded. Embryo 

 exalbuminous; radicle superior. Stem woody. Leaves alternate, stipulate. 



Trees or shrubs, branches scattered, buds scaly. Leaves often sprinkled with 

 resinSus glands, alternate, simple, toothed, the pinnate nerves terminating in the 

 teeth ; stipules free, caducous. Flowers monoecious, sessile, at the base of scaly 

 bracts, in terminal or lateral catkins. — Catkins $ : Scales bearing 2-3 flowers, 

 each accompanied within by 2 or 4 squamnles. Perianth calyciform, regular, 

 4-lobed {Alnus), or reduced to a scale {Betula). Stamens 4, inserted at the base of 

 the perianth-lobes, and opposite to them {Almus) ; or 2, inserted at the base of the 

 scale-like perianth ; filaments bifurcate at the top {Betula) ; anthers basifixed, with 

 cells juxtaposed {Ahms), or separate on the branches of the filament {Betula), dehis- 

 cence longitudinal. — Catkins ? sometimes pendulous, solitary, with membranous or 



