A SECOND OHIO WEED MANUAL. 



339 



Fig. 35- Cypress Spurg-e. 



Repeated cutting and salting is perhaps the best method to destroy cypress- 

 spurge in small patches This will need to be continued until the underground 

 stems have been starved out 

 as with the other plants that 

 have been mentioned. 



SUMAC FAMILY, 

 AXACARDIACLVE. 



196 Sumac ( P) Rhus gla- 

 bra Li. Smooth sumac is a 

 low shrub with pithy stems 

 and pinnate leaves, frequently 

 troublesome in sandy lands 

 and in fence-rows. The taller 

 stag-horn sumac, Rhus typhi 

 na L., similarly occurs in 

 wast j places. Both may be 

 recognized by their dense 

 clusters of bright red, acid 

 berries. The leaves of the 

 European sumac, Rhus cori- 

 aria, are used in tanning. 

 The American species haveuot 

 been utilized for this purpose 

 and are probably valueless. 

 Neither of these species is 

 poisonous to the ordinary per- 

 son. Destroyed by grubbing or by repeated cutting. 



197 Poison Ivy, Poison Oak (Pj Rhus radicans L. The pois.n ivy is a woody 

 vine, climbing over trees and fences by means of its numerous air-roots. It is 

 very frequent on Ohio fences. By reason of some poisonous property, or perhaps, 

 some poisonous exudation, many persons touching it or coming near it suffer 

 from the painful skin eruption known as ivy poisoning. The swamp sumac, 

 Rhus vernix L., also produces similar but more violent poisoning. One can 

 avoid the swamp sumac, but the poison ivy is too common to be escaped altogether. 

 It has three leaflets on each leaf stalk. These are commonly broader toward 

 the base. It is often confused with the Virginia creeper, a harmless and 

 beautiful vine, which h.-^'s, five or more leaflets, broader toward the point. Poison 

 ivy should be killed out by grubbing and fire. Occasional persons can handle 

 it with impunity; they are available in its destruction. Neglect is the only suffi- 

 cient reason for permitting poison ivy to remain. 



MALLOW FAMILY, MALVACEAE. 



198 Low Mallow, Cheeses (b) *Malva rotundifolia L. This mallow is 

 a common garden and roadside weed; it has much scalloped leaves and small 

 white or rose-colored flowers, succeeded by flat, cheese-like masses of seeds, 

 similar to those of the hollyhock. Children sometimes gather and eat these 

 masses, calling them "cheeses." It has a long tapering root, which tits it to 

 grow in trodden earth. 



Seeds very numerous, brown, kidney-shaped, 1-16 inch across, thicker on 

 ':he curved side with notch and beak at the other; apparently mallow seeds 

 retain their vitality for a long- time when buried in the soil. It requires pulling 

 ;r grubbing to destroy the weed in ground that cannot be cultivated. 



