A synopsis of the Characeae'

19641 WOOD: A SYNOPSIS OF THE CHARACEAE 39IIIB. Without cortex; stipulodes in 1 tier (rarely irregular, sparse orabsent, see 15b), 1 per branchlet, opposite (i.e., below eachbranchlet), strongly decumbent ; monoecious; gametangia froma single peripheral cell, and when conjoined generally withoogonium below (position varies in 15b) antheridium ..................................................................................... Genus II(2) LAMPROTHAMNIUM15a. Stipulodes well developed, uniform; oogonia below antheridia.16a. Branehlet segments 4-5 (i.e., 3-4 nodes) ; gametangia atbranchlet nodes and at base of whorl .............................................. 1(20) Lamp. papulosum [Eu, Af, As, Aust, Oc]16b. Branchlet segments 3(-4) ; gametangia not at base ofwhorl ................................................... 2(21) Lamp. hansenii [Eu]15b. Stipulodes irregular, small, some vestigial or absent; oogoniumposition variable, below, beside or above antheridium...................................... 3(22) Lamp. succinctum [ Af, As, Aust, Oc]IIIC. With or without cortex; stipulodes in 1 tier, 2 per branchlet,spreading; monoecious; gametangia each from a separateperipheral nodal cell, generally with central oogonium flankedby 2 lateral antheridia ............................. Genus III(3) LYCHNOTHAMNUS....................................................... 1(23) Lych. barbatus [Eu, Af, As, Aust]IIB. Stipulodes absent or rudimentary; bract-cells normally 2 at a node(occasionally 1 or 3), anterior only, similar in size and shape tobranchlet segment; branchlet segments 2-5; ecortieate; dioecious;bulbils developed, 1- or more-celled; coronular cells spheroid................................................................................. Subtribe II(2) NITELLOPSINAE.............................................................................................. Genus 1(4) NITELLOPSIS17a. Fertile branchlets with 2-3 segments (i.e., 1-2 nodes) ; branchletswithout terminal mucro; bulbils multicellular (stellate).................................................................... 1(24) Nit. obtusa [Eu, As, NA?]17b. Fertile branchlets with 3-5 segments; with or without terminalmucro; bulbils 1-celled (I).18a. Sterile branehlets with 3-4 segments, without terminal mucro;1 bract-cell at a branchlet node; bulbils (I) ............................................................................................. 2(25) Nit. sarcularis [As]18b. Sterile branchlets with 4-5 segments, with short terminalmucro; 1-2 bract-cells at a node; bulbils 1-celled ..................................................................................... 3(26) Nit. bulbilifera [SA]IB. Coronula of 10 cells in 2 tiers; coronula small; branchlets divided, furcate orif monopodial then with lateral rays 2-more-celled ............ Tribe 1(2) NITELLEAEIVA. Branchlets furcate (occasionally with central ray) ; rays verticillate ;antheridia terminal on the end of branchlet rays (or at base ofwhorl) ; oospores laterally compressed; generally without evidentlime, or if present, usually in bands or at dactyl tips. [but see Sect.Migularia, 36h, which nearly matches IVB] ................ Genus I(5) NITELLA19a. Dactyls 1-celled (except N. Inacounii [NA], 21b; N. hookeri [Aust,Oc], 23c) ............................. Subgen. 1(3) NITELLA (Anarthrodactylae)20a. Dactyls obtuse or acute, not acuminate; oogonial convolutionsswelling at maturity ............................................... Sect. 1(6) NITELLA21a. Dactyls 1-celled; branchlets 1 (-2) -furcate.22a. Without mucus; gametangia 1-2(-3) at branchletnodes, sessile ...............................................................1(27) Nitella flexilis [Eu, Af, As, Aust?, NA, SA]22b. With mucus; gametangia 2-3 at branchlet nodes,also stipitate at base of whorl ..................................................................................... 2(28) Nitella mirabilis [As]21b. Dactyls 1 (-2-3) -celled, branchlets (1—) 2 (-3) -furcate............................................................ 3(29) Nitella macounii [NA]