£20 
ADDENDA, 
Serratula arvensis, Willd. 
Icon. FL Dan. 644, Engl. Bot. 975. 
Canada Thistle* 
Flowers purple, smaller than those of Nos. 1, 2, 3 or 4. Since 
printing the foregoing pages I have been directed for this 
plant by Mr. Collins to the neighbourhood of the forge at the 
corner of Vine-street and the Ridge -road, where I found it 
abundant. Mr. C. has found it elsewhere. Perennial. July. 
GYNANDRIA. 
To Cypripedium liumile, page 145. vol. 2, add to 
the English name, ^ JVoali^s Ark* 
The following plants, I am informed by Mr. Col« 
lins, have been found in this neighbourhood: 
viz. 
Aster rigidius. 
Agrostis sobolifera, (flat rock-bridge, Schuylkill.) 
Chara glabra. 
Chara foliosa. 
Erigeron strigosum. 
No. 402. Elephaniophus Carolinianus. 
Rudbeckia fulgida. 
No, 403. Scleria paucifolia. 
Scleria triglomerata. 
No. 404. Uniola gracilis, (Jersey.) 
No. 405. Viscumpurpureum, Muhl. 
N. B. Cy perns minimus, for which I quoted Dr. Clever, on 
the authority of Mr. Niittall, has not, the Doctor informs me, 
been found by him within the limits of this book. 
Rhododendron maximum, or Great Mountain Laurel, I hfeve 
found jii the woods near Gray’s ferry, where it appears to be 
wild. July, 1818. 
