MONOTKOPACEAE 145 



16. DERINGA Adans. 



Involucre none. Involucels usually present. Fruit oblong, glabrous, 

 laterally compressed. Umbels irregularly few-rayed. 



1. D. Canadensis (L.) Kuntze. HONEWORT. l-3 high: leaves 

 3-foliolate: leaflets ovate, sharply serrate, the lateral usually 2-parted 

 and the terminal 3-parted. Common in woods. May-July. 



17. PTILIMNIUM Eaf. 



Involucre and involucels prominent. Fruit ovate, glabrous, strongly 

 corky-winged. Umbels many- rayed. 



1. P. Nuttallii (DC.) Britton. MOCK BISHOP WEED. l-3 high, 

 slender: involucral bracts entire, or sparingly pinnatifid: fruit W-W long. 

 Rare and local in wet, sandy soil near Dodson, at the mouth of Sugar 

 Creek, near Courtney and near Sheffield. June-August. 



FAMILY 94. CORNACEAE Link. 



Shrubs or trees with flowers in heads or cymes. Calyx lobes and petals 

 4-5 each, the latter inserted with the stamens at the base of an epigynous 

 disk. Ovary inferior, 1-2-celled, the cells each containing a solitary pen- 

 dulous ovule. Style one. Fruit a 1-2-seeded drupe. 



1. CORNUS L. DOGWOOD. 



Ours are shrubs with opposite entire petioled leaves and white cymose 

 flowers. Petals and stamens four each. 



Branchlets appressed-pubescent. 



Leaves almost glabrous above. 1. C. Amomum. 



Leaves strongly rough-pubescent above. 2. C. asperifolia. 



Branchlets glabrous. 3. C. candidissima. 



1. C. Amomum Mill. 5-15 high: leaves ovate- lanceolate, more or 

 less pubescent below, acuminate: fruit light blue. Common especially 

 along streams. May-June. 



2. C. asperifolia Michx. 5-15 high: leaves oblong-ovate, pubescent 

 beneath, acuminate : fruit white. Our most common species through- 

 out. May-June. 



3. C. candidissima Marsh. 5-15 high : leaves ovate-lanceolate, 

 acuminate, pale and glabrous beneath: fruit white. Along streams near 

 Tarsney and Atherton. Local. May-June. 



FAMILY 95. MONOTROPACEAE Lindl. 



Saprophytes with scaly, bracted stems and regular perfect flowers. 

 Calyx 2-6-parted. Corolla of 4-6 petals or 4-6 lobed. Stamens 6-12. 

 Ovary superior, 1-6-celled, 4-6- lobed. Stigma rayed. 



1. MONOTROPA L. 



Flowers solitary Calyx of 2 sepals. Petals separate above. Ovary 

 5-celled. 



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