REPORT OP THE STATE BOTANIST 1903 41 



some of the fruit without pressing. It is iinportaut that the 

 three collections be made from the same tree or shrub in order to 

 avoid the danger of confusing two or more closely related species. 

 Sometimes two or more species grow together in one clump and 

 in such cases special care is necessary lest the intermingled 

 branches lead to inextricable confusion of species. To guard 

 against any slip of memory it is well to mark the trunk of every 

 tree or shrub from which specimens are taken, giving to each a 

 number corresponding to a number attached to the specimens 

 taken from it. With a pocket knife shave the rough bark from a 

 small place on one side of the trunk and inscribe the number on 

 this smooth place. It is well in every case to select the same side 

 of the trunk, for example, the north side. Then no time need be 

 lost in looking for the mark on the other sides. 



Because the branches are often coarse and crooked and armed 

 with stout spines, strong pressure is necessary to make good 

 herbarium specimens of them. A screw press is recommended for 

 this purpose. It is also well to loosen the spines by partly split- 

 ting them from the branch before putting the samples in press. 

 It is desirable to know the date of each collection. It should 

 therefore be recorded on the ticket. 



PIIUINOSAE 



Fruit medium, red when ripe, pruinose; stamens 10-20; leaves 

 thick or subcoriaceous, commonly bluish green, glabrous when 

 mature. 



The pruinosity of the unripe fruit is one of the most available 

 characters by which to recognize the species of this grouj). The 

 two species here described differ in the number of their stamens 

 and the color of their anthers. 



Stamens 20, anthers pale yellow or whitish C. c o n j u n c t a 

 Stamens 10, anthers pale purple or pink C. d i s s o n a 



Crataegus conjuncta Sarg. 



Conjoined tliorn 



Rhodora, 5 : 57 



Large shrub 8-12 feet tall with widely spreading or ascending 



branches; leaves ovate, broadly ovate or oval, acute or subacu- 



