REPORT FOR 1913. 



399 



Potamogeton natans L., forma. [Ref. No. 4779.] Great 

 Bedwyn, Wilts. C. P. Hurst. See Report, p. 290, 1912, where by a 

 critic it was referred to P. polygonifolius. The specimens were in a 

 very young condition, but in the fresh state, as sent to me by Mr 0. 

 P. Hurst, showed the characteristic jointed petiole of natans. Older 

 specimens from the same locality sent by Mr Hurst have been 

 submitted to Mr A. Bennett, who agrees to its being natans. 



Azolla caroliniensis Willd. Report 1912, p. 220. Suleham, 

 Berks. Y. Murray. This year I obtained it in good fruit, and Mr 

 N. E. Brown refers it to A. filieuloides Lam. 



Ulmus Plotii Druce. See Report, p. 30, 1911. Fineshade, 

 Northants ; Sawbridgeworth, Essex S. [Ref. No. 6608.] State- 

 ments have been made by Mr A. Henry and Dr Moss that the 

 Elm figured and described in Plot's Nat. Hist. Oxf. 158, 1677, is U. 

 viminalis. When I described the above tree I was conversant with 

 the practically contemporaneous specimen in Herb. Dubois at Oxford 

 collected by the Rev. W. Stonestreet about 1 700 and labelled by him 

 Ulmus folio angusto glabro Plot, which is similar to these. 

 Fortunately I was able to subsequently examine Plot's plants, which 

 are preserved in Herb. Shane at Cromwell Road, and which are 

 named by Bobart. Those supposed not to have been previously 

 described are marked with an *. The elm specimen is labelled 

 * Ulmus folio angusto glabro. It is not U. viminalis, and is my U. 

 Plotii. It must be remembered that the leaves gathered at different 

 seasons and from different parts of the same tree vary considerably. 

 It has been asserted that U. Plotii is synonymous with U. minor 

 Miller, but although there seems to be some presumptive evidence 

 from its localities, yet Miller's descriptions and synonyms for his elms 

 are so muddled and inadequate that various authors give different 

 identifications. For instance, Dr Moss is quite certain that the 

 common English elm is Ulmus campestris Miller, while Mr Henry 

 asserts that it is U. sativa Miller. Dr Moss asserts that my U. Plotii 

 is U. sativa Miller, while Mr Henry says it is U. minor Miller. Plot 

 himself says that his " narrow-leaved elm, which also being smooth," 

 is distinct from U. minor of Gerard and Parkinson, and that it grows 

 wild in the coppices of the Park at Hanwell, near Banbury. It must 

 be borne in mind that Goodyer supplied the description of the elms 



