




60 Rhodora Re 
In West Virginia Thuja is known from but two localities, in the 
extreme Northeast: Knobly Mountain in Mineral County and near — 
Petersburg in Grant County.' Knobly Mountain extends across — 
Mineral and Grant Counties and consists, according to Darton & . 
Taff, of Silurian limestones and calcareous sandstones,’ while Peters- — 
burg is on the South Branch of the Potomac, which drains these and 
the caleareous Devonian sandstones and shales. 
“This is about the rarest tree in North Carolina... .It is said t to 
occur in only a few places, as on Cripple Creek and Linvils River, 
on limestone soil” *; while in Tennessee it is only “along Holston 
River [see above] in the mountains,’ the Holston in Tennessee 
flowing through a highly calcareous region, the rocks, as nia : 
by Keith,® being chiefly Cambrian and Silurian limestones. 
In Ohio Thuja is known only in “Champaiga, Franklin, Greene, 
Highland, Adams” counties;® Orton, on his map of the Limestone 
Formations of Ohio,’ showing Champaign and Greene Couaties a 
wholly limestone, Highland and Adams almost wholly so, and the ve 
western half of Franklin County calcareous nae 
In Indiana Thuja is known only in Lake € ounty,® which is Silurian, : oe 
although thinly covered at the north by the wind-blown sand-dunes 
beside Lake Michigan. The “Tamarack-Arbor-vitae swamp is OF 
the eastern boundary” of the sand dunes where Pinus Banksiana ee 
abounds, but not on the dunes themselves. Here, however, i, a 
land informs us, “The Arbor-vitae trees are not in the best 
dition,” ® although he ascribes their poor condition to the cutting of a 
ditch some distance away. Boe 
So much for the southern colonies of Thuja occidentals. Now ae 
turning in the opposite direction we find a strikingly similar a s 
to calcareous soils of the extreme northern colonies. can. (Cele 





hardly enters the southern limits of the peninsula. 
south of the mouth of the Rupert River, at the foot of -_ Bey 
1 Millspaugh, Living Flora of W. Va. 199 (1913 
2 Darton & Taff, Piedmont Folio (no. 28), Geol. Atlas U.S 
5 Coker & Totten, Trees of 
‘ Gattinger, Flora of Tenn. 32 (1901) 996) 
¢ Arthur Keith, Morristown Folio (no. 27), Gecl. Atlas U. 8. (890). 
* Shaffner, Cat. Ohio Vase. Pl. 126 (1914). 
nena sensi rw Eocene 
Indiane Sta - Rep. xi. ia (1912). 
srnamanhanry Am. a so Li apd (912 
S. (1896). 
