BETULACEAE. 121 



BETULACEAE. Birch Family. 



Wind-pollinated deciduous trees or shrubs with alternate simple petioled 

 g and deciduous stipules. Flowers monoecious, mostly in catkins, flowering 

 in late winter before the leaves appear. Staminate catkins elongated, pendu- 

 lous, falling after flowering. Ovary 2-celled, one seed in each cell. Fruit a 

 1-celled 1-seeded nut or nutlet. 



Fruit an acorn-like nut in a foliaceous tubular involucre 1. Corylus. 



Fruit a margined or winged nutlet, many in a woody cone 2. Alnus. 



1. CORYLUS L. Hazelnut. 

 Leaves thinnish, toothed. Stamens 4 (seemingly 8) ; filaments forked with 

 the undivided portion obsolete in ours; calyx none. Pistillate flowers several 

 in a scaly bud. 2 to each bract, each flower with 2 bractlets; calyx adnate to 

 ovary and without limb; style short, stigmas 2, red, slender, elongated. In- 

 volucre formed of the enlarged and united bractlets. (Greek korus, a helmet, 

 from the involucre.) 



1. C. rostrata Ait. var. calif ornica A. DC. Shrub, 6 to 10 ft. high; leaves 

 roundish to obovate, 1% to 2 1 / 4 in. long; involucre % to 1 in. long; nut sub- 

 globose, 6 lines in diameter. 



Hill country. Coast Ranges and Sierra Nevada. Feb. -Mar. 



2. ALNUS Hill. Alder. 

 Bracts of staminate catkins covering 4 bractlets ; flowers 3 in the axil of 

 each bract; calyx 4 (or 6) -parted; stamens 1 to 7. Pistillate catkins erect, 

 spike-like, ripening into woody cones, the bracts and bractlets united into 

 5-lobed scales persistent on the axis; flowers 2 in the axil of each bract; peri- 

 anth none; styles 2. (The Latin name.) 



Leaf-margin plane, with small scattered glandular teeth; bracts of staminate catkin 

 obtuse; stamens 2, sometimes 3, 1, or 4 1. A. rhombifolia. 



Leaf-margin coarsely toothed, the entire margin with a narrow underturned edge: bracts 

 of staminate catkin acute or acutish; stamens 4, rarely 3 2. A. rubra. 



1. A. rhombifolia Nutt. White Alder. Tree 30 to 80 ft. high; bark 

 whitish or gray-brown ; leaves oblong-ovate or -rhombic, tapering more or less 

 to base and apex, 2 to 4 in. long; cones ovoid, 5 to 9 lines long. 



Banks of rivers and living streams; Sierra Nevada canons; Great Valley; 

 ( oast Kanges except in narrow coast strip occupied by Eed Alder. 



2. A. rubra Bong. Eed Alder. Tree 30 to 90 ft. high; bark very white 

 or white mottled; leaves 2 to 6 in. long, elliptic-ovate, often rusty beneath, 

 the coarse teeth again finely toothed; cones oblong-ovoid, % to 1% in. long. — 

 (A. oregona Nutt.) 



Deep cool canons or moist flats along the coast : Santa Inez Mts. to southern 

 Alaska. Abundant from Marin to Humboldt cos., where it forms pure groves 

 of singular beauty in marshy bottoms near the sea. Also called Oregon Alder. 



A. texuifolia Nutt. Forming shrubby thickets. — Sierra Nevada, 6,000 to 

 I ft. 



FAG ACE AE. Oak Family. 



Trees or shrubs with alternate simple leaves and promptly deciduous stipules. 

 Flowers monoecious, apetalous, appearing with the leaves in the deciduous 

 kinds. Staminate flowers in catkins; calyx parted into several lobes; stamens 

 4 to 12. Pistillate flowers 1 to 3 in an involucre of imbricated scales, tin- in- 



