Art. VI. An Account of two North American Species of Rottböllia, discovered on the Sea-coast in the State of Georgia.
Art. VI. An Account of two North American Species of Rottböllia, discovered on the Sea-coast in the State of Georgia, by Dr. William Baldwin, of Philadelphia.
Flowers in pairs, or two from each joint of the rachis, one neutral. The neutral, or imperfect flowers, pedicillate.
Rottböllia corrugata.
Culmo erecto, compresso, sulcato, glabro, ramoso: foliis longis angustisque: spicis sub-compressis, nudis super uno latere, solitariis et terminalibus, supremis approximatis: calycis bivalvis, valva exteriori transversè corrugata et longitudinaliter rugosa: corolla trivalvis.
Culm erect, compressed, sulcate, smooth, ramose: leaves long and narrow: spikes slightly compressed, naked on one side, solitary and terminal, approximating towards the summit: calyx 2-valved, the exterior valve transversely corrugate, and longitudinally wrinkled: corolla 3-valved. Vid. Nuttall's North American Genera, v. I. p. 84.[51]
Culm two to three feet high, with a very solid exterior, but spongy within, compressed, and deeply grooved on its inner angle the whole length between the joints. Leaves long, narrow, and acute, scabrous on the margin and midrib. Sheaths compressed, corresponding with the culm, shorter than the internodes, open, with membraneous margins. Peduncles short, clothed with a thin membraneous acute pointed sheath, which generally encloses also the base of the spike. Spikes two to three inches long. The flowers are arranged in alternate order, but occupy only one side of the rachis, as in the R. dimidiata. The neutral florets, or clavate pedicels, are joined laterally to the perfect flowers. Articulations of the rachis remarkably tumid, attenuated beneath, flat on the interior side, exteriorly convex, scabrous, and longitudinally striate. The exterior valve of the calyx, in the perfect flowers, is ovate, obtuse, very thick, cartilaginous, the inner margin inflected, and deeply marked on its outer surface with from three to five corrugations, with longitudinal ridges between them; the interior valve is smaller, of equal length, acute, ruled, coriaceous, smooth, and with the inner margin also inflected. The valves of the corolla are membraneous, ovate, acute, white, shorter than the calyx, the exterior one the longest. The neutral florets are sometimes male, but most commonly consist of nothing more than a 2-valved calyx, the valves equal, gaping, scabrous, and much smaller than those of the perfect flower. Stamens 3, very short. Anthers twin, yellow. Styles 2, rather longer than the stamens. Stigmas small, plumose, dark purple.
Discovered between St. Mary's and Jefferson, in Camden county, Georgia, on the 13th of July, 1813. Inhabits flat, moist pine barren. I have not seen it "on the sea-coast of Florida."
OBSERVATIONS.
It will be perceived that my description of this plant differs materially from that of Mr. Nuttall. This has unavoidably arisen from my having attended to it in its living state, and from his not availing himself of the information which it would have afforded me pleasure to have communicated, had he done me the favour to have requested it, or informed me of his wish to publish an account of plants thus obtained. He has called the culm solid, leaves rather short, spikes cylindric, axillary, the flowers and rachis entirely smooth, pedicel of the neutral flower emarginate, outer valve of the hermaphrodite calyx acute, the valves of the corolla obtuse, and the styles very short. I have not been able to confirm the above characters, nor do I find them even in the dried specimens. Besides, he has omitted to inform us that the rachis is naked on one side. This is a most important and prominent specific character, the omission of which would necessarily lead to much doubt in identifying the species. What he means by stating that the "outer valve of the hermaphrodite flower is 3-valved," I cannot imagine, nor do I comprehend what is intended by an "exterior auxiliary valve, or neutral rudiment; nearly the length of the calyx." I have noticed in a single instance, connected laterally with the corolla of the perfect flower, two very delicate, narrow, acute pointed bodies, the length of the outer valve, and of the same quality and appearance; but these I have considered as accidental, and cannot perceive any thing about them like neutral rudiments. Nor can I consider the articulations of the rachis as "deeply excavated." They are, as already stated, flat on the inner side, and constitute from their flexuous form, position, and connexion with the pedicels of the neutral florets, an arch, in which the perfect flowers are situated.
Rottböllia ciliata.[52]
Culmo erecto, tereti, glabro, ramoso: foliis angustissimis, brevibus: spicis cylindricis super pedunculis teretibus longis, solitariis terminalibusquæ: calycis bivalvis, margine valva exteriori ciliata: corolla bivalvis.
Culm erect, terete, smooth, ramose: leaves very narrow, short: spikes cylindrical upon long terete peduncles, solitary and terminal, calyx 2-valved, the margin of the exterior valve ciliate: corolla 2-valved.
Root perennial. Culm two to four feet high, generally ramose, solid, and terete, except that between the joints where the branches originate, it is grooved on the inner side, and often ciliate on its angles near the joints. The branches originate towards the extremity, commonly from two to three in number, each supporting a single terminal spike. Leaves very narrow, acute, comparatively short, those beneath much the longest, rigid, somewhat involute, and sharply serrulate towards the apex. Sheaths rather shorter than the internodes, open to the base, but closely embracing the culm. Spikes 3 to 5 inches long, the peduncles clothed with a very delicate acute pointed sheath, which embraces it so closely as almost to elude observation, varying much in length, but seldom extending to the base of the spike. Peduncles scabrous near the spike. Flowers alternate, the male or neutral florets situated on one side of the rachis. Rachis compressed, slender, flexuous, hairy on its exterior surface. Pedicel of the neutral florets also compressed, and hairy on its exterior surface. Valves of the calyx nearly equal, lanceolate, acute, coriaceous, polished, the inner margin of each inflected. The exterior margin of the outer valve finely ciliate towards the apex. Valves of the corolla lanceolate, acute, membraneous, nearly the length of the calyx. The male or neutral, are rather smaller than the hermaphrodite flowers. Stamens 3, very short. Anthers twin, purple. Styles 2, excerted, plumose, dark brown.
Discovered in flat pine barren on the north side of Satilla river, in Georgia, on the 21st of October, 1815.
GENERAL OBSERVATIONS.
These plants are unquestionably allied to andropogon in their mode of flowering, but have nevertheless sufficient essential characters to distinguish them. In habit, they appear but slightly similar. They differ principally from their congeners in the pedicellate character of their neutral florets. The spikes are not axillary in either of them. The branches are axillary, of which several sometimes originate from the same axil in the R. corrugata. Each spike, when fully evolved, is not only pedicellate, but the pedicel, or peduncle, is connected with a culm containing one, two, or more joints.[53] The culm is not compressed, nor the leaves long in the R. ciliata, as stated by Mr. Nuttall, who appears to have confounded the two species in these, and some other instances. The joints of the rachis in both are fragile, the joints of the culm in neither.
Another species noticed by Michaux, and included in all our books as the R. dimidiata, L. has long been familiar to the southern botanists. Whether this be the dimidiata found also on the sandy shores of India, or the compressa of the same country, as suggested by Mr. Elliott, or a species distinct from either, I am not prepared to determine. But I have collected this plant in the Bermudian Isles, at Rio de Janeiro, and Bahia, on the Brazilian coast, and lastly on the island of Flores, near one hundred miles from the mouth of the Rio de la Plata, as well as on the main in the Banda Oriental.