112 Kansas Academy of Science. 



646. Limnobium spnngia Rich. Frogbit. Stagnant water, Johnson 

 county; rare, and only to be found in special years, when the weather is 

 favorable. 



Order XXIII. ALISMALES. The Alismads. 



Inflorescence in spikes, racemes, or panicles; flowers perfect or unisexual. 

 Perianth single or double; calyx of three persistent herbaceous sepals, and 

 corolla of three deciduous showy petals, or none. Stamens three, six or 

 more, sessile or with very short filaments; anthers with inconspicuous con- 

 nectives. Carpels three to many, distinct, though often coherent during 

 anthesis; ovulary superior; style short; stigma discoid; ovules solitary or 

 few. Fruit a head of achenes, or capsular. Hydrophytes, from rootstocks 

 usually tuber-bearing; caulescent or scapose. Leaves basal, alternate, 

 sheathing; forms various — laminar, laminodiar, phyllodiar, or bladeless, 

 sometimes juncoid, with spongy tissue; laminodia with their distal ends in 

 all degrees of expansion, from not at all or only slightly, as in Triglochin, 

 to a broad auriculate prolamina, closely simulating a true leaf blade, as in 

 Sagittaria; nervation prominent, parallel, radiating, campylodromous, or 

 convergent. 



Family 46. Scheuchzeriace^. Arrow-grass Family. 

 Perennial marsh herbs, with semiterete rush-like or tapering bladeless 

 laminodia, with expanded open sheaths. Flowers perfect, in spikes or 

 racemes, without subtending bracts. Perianth in two series, the inner 

 (corolla) deciduous. Stamens six; anthers sessile, bisporangiate, extrorse. 

 Carpels three or six, unilocular, one- to two-ovuled, somewhat united till 

 maturity; stigmas sessile. Fruit follicular or capsular; seeds anatropous; 

 embryo straight; endosperm none. 



647. Scheuchzeria palustris L. Arrow-grass. Reported from marshes 

 of central Kansas; possibly the same as the next. 



648. Triglochin maritima L. Salt-marsh Arrow-grass. Salt marshes in 

 the sandy salt region of central Kansas; frequent. July. (AS) 



Family 47. Alismace^. Arrow-head Family. 

 Annual or perennial scapose aquatic herbs, with roots fibrous or stolon- 

 iferous. Leaves various, basal, sheathing, ordinarily long-petioled, with 

 broadly expanded, auriculate-lobed, cordate, ovate, or lanceolate, or even 

 without expansion of the distal ends; sometimes reduced to stipular phyl- 

 lodia; no dividing line can be drawn between the extreme forms. Inflores- 

 cence often in verticils of three, subtended by bracts. Flowers 

 actinomorphic, pediceled; when monoecious the uppermost flowers are 

 staminate, the lower carpellate or perfect. Perianth of three persistent 

 green herbaceous sepals and three deciduous chromoplastic petals, imbri- 

 cate in prefloration. Stamens six or more, distinct, in two whorls; anthers 

 bisporangiate, extrorse, dehiscing by lateral vertical slits. Carpels nu- 

 merous; ovularies superior, distinct, unilocular; ovules erect, campylotro- 

 pous, solitary or several in each ovulary. Fruit a head of turgid achenes; 

 seeds uncinate-curved, ribbed; embryo horseshoe-shaped; endosperm none. 



649. AHsma plantago L. Water-plantain; Alisma. Mud and shallow 

 water, in nearly every county; occasional. June. (ASU) 



650. Helianthium tenellum Britt. ' (Alisma Martens.) Spear-head. 

 Mud* occasional; not often recognized. April. (AS) 



