y 



THE MAPLE FAMILY 



ACERACEiE Saint Hilaire 



HIS family consists of but 2 genera, the Asiatic Dipteronia of Oliver, 

 and the Maples, including in all about 100 species of trees or shrubs, 

 many of which contain a saccharine sap which upon concentration 

 becomes the favorite Maple syrup, or on solidification is known as 

 TVIaple sugar. The timber of the maples is also highly valued. As ornamental 

 and shade trees they are probably more used than any other single genus of our 

 flora. 



The AceracecB have opposite, simple leaves, which are usually palmately lobed, 

 rarely entire or pinnate. The flowers are regular, polygamous or dioecious, borne 

 in axillary or terminal corymbs or racemes. The calyx is usually 5-parted, mostly 

 colored and deciduous; the disk, if any, is cup-shaped, usually lobed; corolla want- 

 ing or, if present, consisting of the same number of petals as there are calyx- 

 lobes and alternate with them; stamens as many as the calyx-lobes, or often 8, 

 their filaments thread-Hke, distinct, sometimes very short; anthers introrse, versa- 

 tile; ovary free, 2-lobed and 2-celled; styles 2, usually united; stigma 2-cleft. The 

 fruit usually consists of 2 long- winged samaras with nut-Hke bases; seed i, rarely 

 2, compressed, without endosperm; the embr}^o has thin cotyledons. 



Our arborescent forms are best treated as one genus, although some authors 

 group the Box elders, or Ash-leaved maples, the compound-leaved species, into 

 another genus under the name Rulac Adanson or Negtmdo Moench. 



THE MAPLES 



GENUS ACER [TOURNEFORT] LINN^US 



CER comprises nearly 100 species of trees or shrubs, with few excep- 

 tions confined to the northern hemisphere, throughout which they are 

 widely distributed. Numerous fossil species have also been de- 

 scribed. 

 The name is the ancient Celtic name of the Maple, A. Pseudo-Platanus Linnaeus 



being the type. 



The following North American trees are known: 



A. Leaves simple, palmately or radiately veined. 

 a. Flowers in terminal racemes, panicles or corymbs, unfolding after 

 the leaves, or with them. 

 * Flowers panided or racemose. 



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