39 



Dodonaea microcarya Small, sj). nov. A shrub or a small Iroe 

 6 m. tall, with a trunk diameter up to 15 cm., the bark rough, 

 the twigs reddish, glabrous: leaves numerous; blades cuneate 

 to obovate-cuneate or broadly spatulate, 1-5 cm. long, usually 

 less than 4 cm., thick, entire, rounded or emarginate at the apex, 

 glabrous, short-petioled: flowers not seen; fruit suborbicular 

 in outline, often somewhat depressed, less than i cm. wide, 

 usually 5-7 mm. across the wings, emarginate at the apex and 

 tipped with the blunt style base, short-stipitate, the pedicel as 

 long as the fruit or shorter; seeds subglobose, nearly 2 mm. in 

 diameter, smooth but scarcely shining. — Hammocks, Big Pine 

 Key, Florida. 



This plant has no close relative among the Dodonaea of the 

 American tropics. Its foliage somewhat resembles that of the 

 Hawaiian Dodonaea spatulata, but the leaf-blades are more de- 

 cidedly cuneate and the fruits are much smaller. The type 

 specimens collected on the northern part of Big Pine Key, 

 Florida, May 8, 1919, by John K. Small, Alfred Cuthbert, and 

 Paul Matthaus, number 9105, are in the herbarium of the New 

 York Botanical Garden. 



ILLUSTRATIVE MATERIAL OF GAPS AND TRACES 

 IN TEACHING PLANT ANATOMY. 



C. L. Wilson. 



As every teacher of plant anatomy knows, it is easy to demon- 

 strate leaf and branch gaps as seen in a cross section of the stem. 

 This is usually accomplished by free-hand sections through the 

 stem, the sections being laid out in series until the whole of the 

 gap is seen, from the passing out of the trace to the closing of 

 the gap. Most herbaceous stems will serve for this purpose, as 

 well as some woody stems in which little secondary growth has 

 occurred. Fern rhizomes, particularly those of Dennstaedtia and 

 Adiantum, are especially effective, since there are no branch 

 traces to confuse the beginning student. 



It is not so easy, however, for the beginner to visualize the 

 nodal region of a stem as it would appear in face view with the 

 cortex removed. Such a stem maybe found in mullein {Ver- 

 hascum Thapsus L.). In old stems which have been exposed to 

 the action of the weather for a vear or longer, it will be found 



