CORNACEAE. 689 



segments dentate, lobed or pinnatifid ; upper leaves less divided ; bracts of the in- 

 volucre parted into linear or filiform lobes; umbels 5-10 cm broad; ray s numerous ; 

 flowers white, the central one of each umbel often purple, that of each umbellet 

 occasionally so, all rarely pinkish; fruit 3-4 mm. long. In fields and waste places, 

 common throughout our area, often a pernicious weed. Nat. from Europe. The 

 original of the cultivated Carrot. June-Sept. 



Family 3. CORNACEAE Link. 

 Dogwood Family. 



Shrubs or trees, with simple opposite, verticillate or alternate, usually 

 entire leaves, and regular flowers in cymes, heads or rarely solitary. 

 Calyx-tube adnate to the ovary, its limb 4~5-dentate, or none. Petals 

 generally 4 or 5, sometimes wanting, valvate or imbricate, spreading, in- 

 serted at the base of the epigynous disk. Stamens as many as the petals 

 or more numerous, inserted with them ; filaments subulate or flat. Ovary 

 inferior, i-2-celled in our species; style I, short or elongated; ovules I 

 in each cavity, pendulous, anatropous. Fruit a drupe. Seeds oblong; 

 embryo nearly as long as the endosperm; cotyledons foliaceous. About 

 16 genera and 85 species, most abundant in the northern hemisphere. 



Flowers perfect, 4-parted ; ovary 2-celled. i. Cornus. 



Flowers polygamous or dioecious; petals minute or none; ovary i-celled. 2. Nyssa. 



i. CORNUS L. (See Appendix.) 



Flowers small, white, greenish or purple, in cymes, or heads, the latter involu- 

 crate with large white bracts in our species. Calyx tube top-shaped or campanu- 

 late, its limb 4-toothed. Petals 4, valvate. Stamens 4. Ovary 2-celled; stigma 

 truncate or capitate; ovules I in each cavity. Drupe ovoid or globular, the stone 

 2-celled and 2-seeded. [Greek, horn, from the toughness of the wood.] About 

 25 species, natives of the north temperate zone, Mex. and Peru. Besides the fol- 

 lowing, some 7 others occur in western N. Am. 



* Flowers capitate, with an involucre of 4-6 large white bracts. 

 Low herbaceous shrubs ; rootstocks slender. 



Upper leaves verticillate; flowers greenish. i. C. Canadensis. 



Leaves all opposite; flowers purple. 2. C. Suecica. 



Tree or large shrub; flowers greenish yellow. 3. C.florida. 



* * Flowers cymose, white, not involucrate. 

 Leaves opposite. 



Leaves downy-pubescent beneath, at least when young; (sometimes glabrate in No. 5)0 

 Leaves broadly ovate or orbicular; fruit blue. 4. C. circinata. 



Leaves ovate or ovate-lanceolate. 



Fruit blue; stone pointed at the base. 5. C. Amomum. 



Fruit white. 



Stone globose, broader than high. 6. C. asperifolia. 



Stone compressed, much broader than high. 7. C. Baileyi. 



Leaves glabrate, or minutely pubescent beneath. 



Leaves ovate, short-pointed ; twigs purple. 8. C. stolonifera. 



Leaves ovate-lanceolate, acuminate. 



Fruit white; twigs gray. 9. C. candidissima, 



Fruit pale blue; twigs reddish. 10. C. stricta. 



Leaves alternate, clustered at the ends of the flowering branches, u. C. alternifolia. 



i. Cornus Canadensis L. Low OR DWARF CORNEL. BUNCH-BERRY. 

 (I. F. f. 2710.) Flowering stems scaly, 7-30 cm. high. Rootstock nearly hori- 

 zontal; leaves verticillate at the summit, or sometimes I or 2 pairs of opposite ones 

 below, sessile, oval, ovate, or obovate, pinnately veined, glabrous or minutely ap- 

 pressed-pube scent, acute at each end, 2-8 cm. long; peduncle 1-4 cm. long; invo- 

 lucral bracts ovate, 8-12 mm. long; flowers greenish, capitate; petals ovate, one of 

 them with a subulate appendage; fruit globose, bright red, about 6 mm. in diame- 

 ter; stone smooth, globose. In low woods, Newf. to Alaska, N. J., Ind., Minn., 

 Colo, and Cal. Rarely the upper leaves are opposite. May-July, 



