IOWA ACADEMY OF SCIE^JCES. 



6J 



streams or partially opou prairies. Quercus oblusiloba. Qroton texeiisis, 

 tiolanum ekagnifolium abound. Ilex cnssine occurs on sandy ridges near 

 the sti-eams. The climate' varies greatly. Along the Red river in Decem- 

 ber the mean is 41 degrees. The minimum for the same month was 

 20; the maximum, 76°. At Corsicana the extremes are G=^ and 8(P, with a 

 mean of 47.4^. The amount of precipitation also varies greatly; thez'e 

 being much more dryness in the region about Austin, than Dallas and 

 Denison; at the latter place it was 46.3 inches in 1880; at San Antonio, 

 about (ifty miles west of San Marco.s, the rainfall for the same year was 40 

 inches, distributed somewhat more evenly than in Denison. The amount 

 of drouth some plants can stand is somewhat surprising. Notwith- 

 standing the fact that in 1889 when I visited Texas, there had been a drouth 

 of seven weeks, common plants like Sabbalia campestris, (Jrolon capitatum, 

 vai'., Undheimeri, Castilleja indi'visa, Eryngium leavenworlhii and many oth- 

 ers looked fresh and bright in the morning. This is partly owing to the fact 

 that the heavier soils are poorly drained and the bard pan contains consid- 

 erable moisture even during very dry weather. In "black waxy" soils 

 the water was so abundant in some cases that drops could be found on the 

 roots of some plants when growing close to the rotten limestone. Annuals 

 usually suffer much more from long standing drouths than perennials. 

 '1 hey flower early and mature their seeds, and after the August or Septem- 

 ber rains it is not an unusual thing to see cotton and corn fields covered 

 with various grasses like Pajiicum sanguinale aud P. glabrum, Elusine 

 indica, and Leptochloa mucronnta, affording good forage. Weeds of various 

 kinds become surprisingly numerous at such times. 



In the arrangement of orders and genera Gray's systematic works have 

 been followed. Smue use has also been made of Coulter's contributions, U. 

 S. Nat. Museum, Vol. II, Nos. 1 and 2. The nomenclature of these authors 

 has been followed in the main. Where the specimens have been preserved 

 they are marked (P.). The grasses were identified by Dr. Vasey some four 

 years ago. Bhamri'i cecv and Ilici?iece- by Prof. Trelease. 



DICOTYLEDENOUS PLANTS. 

 RANUVCULACE.l!:. 



(1) Clematis pUcheri, Torr. & Gray. (Leather Flower ) Clay Station, 

 Burleson county. Rocky woods. (P.) 



iMAGNOLIACEiE. 



(2) Magnolia grandi flora. (Large Magnolia.) Only as a cultivated tree. 

 Yarborough, Grimes county. (P.) 



ANONACCE^:. 



(3) Asimina triloba, Dunal. Denison, Grayson county. 



MENISPEUMACEvE. 



(4) Coccubis caroli7ius, DC. Navasota, Grimes county; College Station , 

 Brazos county. Common in low places along streams climbing over 

 bushes. (P.) 



'Hilgard Cotton Production. Tentli annual report. Pt. I. p. O'J. 



