336 LEITNEKIACEAE 



elongated, the margins slightly thickened, undulate, deciduous: stipules want- 

 ing. Aments dioecious, appearing before the leaves : staminate with acuminate 

 concave imbricated bracts inserted on a stout pubescent rachis : perianth wanting : 

 stamens 3-12, inserted on the receptacle-like stalk of the bract : filaments filiform- 

 subulate, slightly dilated at the base, incurved : anthers introrse, notched at the 

 apex. Pistillate aments mostly near the ends of the branchlets, the bracts like 

 those of the staminate, but acute, subtending the minute perianth of gland-fringed 

 scales. Gynoecium a single carpel. Ovai-y sessile or nearly so, 1-celled, ob- 

 lique : style eccentric, constricted at the junction with the ovary : stigma in- 

 trorse. Ovule solitary, ascending, half-anatropous. Fruit a collection of drupes 

 each subtended by the little-changed bract. Embryo with cordate cotyledons. 



Family 1. LEITNERIACEAE Drude. Corkwood Family. 



One genus in the southern and south-central United States. Its morpholog- 

 ical characters associate it with Myricaceae^ while its anatomy is nearer to that 

 of the Hamamelidaceae. 



1. LEITNERIA Chapm. 

 Characters of the order. 



1. Leitneria Floridana Chapm. A shrub or small tree, reaching a height of 7 m. 

 and a maximum trunk diameter of 14 cm., with a gray bark and very light wood. 

 Leaf-blades narrowly elliptic, oblong or elliptic-lanceolate, or rarely oval, 10-20 cm. 

 long, mostly acute, sometimes obtuse or apiculate, becoming thickish, rugose, glabrous 

 above except the midrib and lateral nerves, densely pubescent beneath ; petioles 3-6 

 cm. long, pubescent: staminate aments cylindric, 3^ em. long, pubescent, with tri- 

 angular-ovate, acuminate bracts varying from 4-5 mm. in length: pistillate aments 

 smaller than the staminate, their bracts ovate, acute, pubescent: ovary pubescent: 

 stigma rather foliaceous: drupes elliptic, 15-17 mm. long, slightly compressed. The 

 wood weighs about 12| pounds to the cubic foot, being lighter than cork and probably 

 the lightest wood known. 



In swamps, southern Missouri to Texas and Florida. Spring. 



Order 5. MYRICALES. 



Dioecious or sometimes monoecious aromatic shrubs or small trees, commonly 

 with a smooth bark. Leaves alternate, mostly without stipules: blades simple, 

 resinous-dotted. Staminate flowers in elongated axillary aments, each consist- 

 ing of 2-8 stamens on a bract. Filaments short, someAvhat united at the base. 

 Anthers extrorse. Pistillate flowers in short axillary aments. Gynoecium of 2 

 united carpels on a bract, subtended by two braetlets and surrounded by 2-8 

 short or elongated scales. Ovary 1-eelled. Stigmas 2, filiform. Ovule solitary, 

 erect, orthotropous. Fruit a nut, whose epicarp often excretes particles of wax. 

 Seed solitary, with a thin-membranous testa. Embryo central. 



Family 1. MYRICACEAE Dumort. Bayberry Family. 

 Characters of the order. 



Leaves witli stipules: blades pinnatifid: scales surrounding the ovary 8, subulate; conspicuous. 



1. COMPTONIA. 



Leaves without stipules; blades entire or toothed: scales surrounding the ovary 2-4, 



very sliort, inconspicuous. 2. Mobella. 



